A rotor concentricity reservation method for a dual-axis compressor tester with same-side input

Abstract

The present application provides a method for reserving rotor concentricity of a dual-axis compressor tester with same-side input, which belongs to aero-engine testing, comprising: determining the thermal expansion displacement of the exhaust duct and the gearbox support structure in the dual-axis compressor tester with same-side input, calculating the thermal expansion displacement of the input flange of the dual-axis compressor test piece and the output flange of the gearbox according to the thermal expansion displacement and the axial distance, and then obtaining an estimated change in cold and hot concentricity; calculating an estimated cold concentricity based on the estimated change in cold and hot concentricity with the hot concentricity being zero, and setting the rotor of the dual-axis compressor tester with the estimated cold concentricity; arranging vibration measurement points and bearing temperature measurement points for testing, judging the operating status of the dual-axis compressor tester by the vibration measurement points and the bearing temperature measurement points, if the operating status meets the requirements, the estimated cold concentricity meets the requirements; if the operating status does not meet the requirements, correcting the estimated cold concentricity.

Description

Technical Field

[0001] The present application belongs to the field of aero-engine testing, and in particular relates to a rotor concentricity reservation method for a dual-axis compressor tester with same-side input. Background Art

[0002] A twin-shaft compressor tester with same-side input typically uses two motors as its power input. After speed increase through a gearbox, the two parallel drive shafts are converted into a coaxial transmission structure with an outer shaft sleeve and an inner shaft, respectively driving the high- and low-pressure rotors of the twin-shaft compressor test instrument (usually consisting of a low- and high-pressure compressor). Because the twin-shaft compressor test instrument and gearbox share a coaxial transmission structure, the shafting system is characterized by numerous branches and a long span, resulting in complex rotor dynamics and, therefore, a high degree of sensitivity to shafting concentricity.

[0003] like Figure 1 The figure shows the shafting and support structure of a typical same-side input biaxial compressor tester. The biaxial compressor test piece 1 is cantilever-supported and secured to the tester's exhaust duct 2 via an exhaust mounting flange. The exhaust duct 2 is secured to the base platform via front and rear supports 4 and 5. The exhaust duct 2 is centrally supported, so its own thermal expansion does not cause changes in the axis position. However, thermal expansion of the front and rear supports 4 and 5 can cause changes in the axis position of the test piece. The gearbox 3 is secured to the base platform via a base 6 and is bottom-supported. Thermal expansion of both the base 6 and the gearbox 3 housing can cause the axis to float upward. High-speed, high-torque transmission is used between the biaxial compressor test piece 1 and the gearbox 3. During installation and adjustment, good concentricity must be ensured between the input flange 7 of the biaxial compressor test piece 1 and the output flange 8 of the gearbox 3 to avoid unnecessary vibration.

[0004] When the dual-axis compressor tester is in operation, the exhaust temperature and pressure are both high. The supporting structures of the exhaust duct 2 and the gearbox 3 are located in a high-temperature environment. The thermal expansion and deformation of the supporting structures will cause the axis to deviate from the initial position. Therefore, it is necessary to reserve the cold concentricity to ensure that the hot shafting is well aligned. However, due to the uneven thermal expansion of each supporting structure, it is difficult to estimate the change in cold and hot concentricity. The existing concentricity reservation method only calculates the thermal expansion and deformation of the exhaust duct and gearbox separately before the test, and performs an initial reservation assessment. However, due to the uneven thermal expansion, the concentricity reserved by this method is poor, and it is difficult to ensure the alignment of the hot shafting. Summary of the Invention

[0005] The purpose of the present application is to provide a rotor concentricity reservation method for a dual-axis compressor tester with same-side input, so as to solve or alleviate at least one problem in the background technology.

[0006] The technical solution of the present application is: a method for reserving rotor concentricity of a biaxial compressor tester with same-side input, comprising:

[0007] S10, determining the thermal expansion displacement in the height direction of the exhaust duct and the gearbox support structure in the biaxial compressor tester with the same input, and calculating the thermal expansion displacement in the height direction of the input flange and the output flange of the gearbox of the biaxial compressor test piece based on the thermal expansion displacement in the height direction of the exhaust duct and the gearbox support structure and the axial distance, thereby obtaining the estimated concentricity change in the hot and cold states;

[0008] S20, calculating an estimated cold concentricity based on the estimated change in cold and hot concentricity, with the hot concentricity being zero, and setting a rotor of the biaxial compressor tester based on the estimated cold concentricity;

[0009] S30, arranging vibration measuring points, bearing temperature measuring points, and support structure wall temperature measuring points in the biaxial compressor tester, operating the biaxial compressor tester for testing, and judging the operating status of the biaxial compressor tester by the vibration measuring points and the bearing temperature measuring points. If the operating status meets the requirements, the estimated cold concentricity meets the requirements; if the operating status does not meet the requirements, the estimated cold concentricity is corrected by using the data from the support structure wall temperature measuring points.

[0010] Preferably, the exhaust duct and gear box support structure includes an exhaust duct front support, an exhaust duct rear support, a gear box support front foot, and a gear box support rear foot.

[0011] Preferably, in step S10, the process of obtaining the estimated cold and hot concentricity variation includes:

[0012] S11, acquiring temperature field data of the exhaust duct and the gearbox support structure, wherein the temperature field data includes temperature variation;

[0013] S12, obtaining structural dimension data of the exhaust duct and the gearbox support structure, including material, height, and axial distance, and obtaining thermal expansion data of the material under corresponding temperature field data;

[0014] S13, calculating the thermal expansion displacement of the exhaust duct front support and the exhaust duct rear support in the height direction based on the temperature field data, structural dimension data and thermal expansion data 、 And the thermal expansion displacement of the gearbox support front foot and the gearbox support rear foot in the height direction 、 ;

[0015] S14, based on the calculation results of the thermal expansion displacement of the exhaust duct and the gearbox support structure and the axial distance, the thermal expansion displacement of the input flange of the biaxial compressor test piece and the output flange of the gearbox in the height direction is calculated. The difference in the thermal expansion displacement of the input flange of the biaxial compressor test piece and the output flange of the gearbox is the concentricity change during the thermal expansion process, thereby obtaining the estimated cold and hot concentricity change: , 、 They are the thermal expansion displacements of the input flange of the dual-shaft compressor test piece and the output flange of the gearbox.

[0016] Preferably, the temperature field data of the temperature variation of the exhaust duct and the gearbox support structure are obtained through CFD simulation calculation, theoretical estimation, and analogy analysis methods.

[0017] Preferably, the thermal expansion displacement of the exhaust duct front support and the exhaust duct rear support in the height direction is 、 And the thermal expansion displacement of the gearbox support front foot and the gearbox support rear foot in the height direction 、 The calculation method is:

[0018] ;

[0019] Where α is the thermal expansion coefficient of the material of the exhaust duct or gearbox support structure;

[0020] ΔT is the temperature change of the exhaust duct or gearbox support structure;

[0021] H Height of the exhaust duct or gearbox support structure.

[0022] Preferably, the thermal expansion displacement of the input flange of the biaxial compressor test piece and the output flange of the gearbox in the height direction is calculated by linear interpolation, that is:

[0023] ;

[0024] ;

[0025] Where L is the axial distance.

[0026] Preferably, the process of correcting the estimated cold concentricity using the data of the support structure wall temperature measurement points includes:

[0027] S31, obtain the concentricity of the rotor of the biaxial compressor tester after the test and the temperature of the exhaust duct and gearbox support structure after the test , according to the exhaust duct and gearbox support structure temperature during the test , estimated cold concentricity C and concentricity after test Estimating hot concentricity during testing , and then get the estimated actual concentricity change ;

[0028] S32, re-evaluate and calculate the cold and hot concentricity variation based on the actual temperature of each support structure during the test, and obtain the cold and hot concentricity variation in the test , The temperature change of the exhaust duct or gearbox support structure during the test;

[0029] S33, estimated actual concentricity change And the change of concentricity in hot and cold states during the test Get the corrected cold and hot concentricity change ;

[0030] S34, calculating the corrected cold concentricity based on the corrected change in the hot and cold concentricity, with the hot concentricity being zero.

[0031] To address the significant concentricity variations caused by factors such as the short axial span of the exhaust duct support structure and high exhaust temperatures in a dual-axis compressor tester, this application comprehensively considers multiple influencing factors, including thermal expansion deformation of the exhaust duct support, the gearbox housing, the gearbox base, and uneven thermal expansion at different circumferential positions, thereby improving the accuracy of the calculation of the variation in concentricity between hot and cold states. Furthermore, this application proposes correcting the variation in concentricity between hot and cold states based on test data, effectively reserving the rotor concentricity of the dual-axis compressor tester and effectively avoiding abnormal phenomena such as shaft vibration caused by poor hot concentricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0033] Figure 1 Schematic diagram of the shafting support structure of a typical same-side input biaxial compressor tester.

[0034] Figure 2 Schematic diagram of the rotor concentricity reservation method for the dual-axis compressor tester with same-side input in this application.

[0035] Figure 3 Schematic diagram of the calculation points for thermal expansion displacement of the biaxial compressor tester with same-side input in this application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0037] For a dual-axis compressor tester, the ambient temperature of the exhaust duct and gearbox support structure is relatively high, and the front / rear supports of the exhaust duct, the gearbox housing, and the base will all experience significant thermal expansion and deformation. Furthermore, the structural form of the same-side input results in a shorter axial span of the front and rear supports of the exhaust duct (approximately 1 / 2 of that of a traditional single-axis structure), and the thermal concentricity changes caused by the uneven thermal expansion are more significant. Therefore, in order to solve the problem of difficulty in evaluating and calculating the rotor concentricity reserve of a dual-axis compressor tester with same-side input, this application proposes to comprehensively consider the thermal expansion and deformation of the exhaust duct support, gearbox housing, and gearbox base to improve calculation accuracy and avoid the problem of large deviations caused by single-factor calculations. At the same time, the concentricity reserve is corrected based on test data to further optimize the hot concentricity and ensure the hot alignment of the shaft system.

[0038] Concentricity reservation means that when adjusting the cold concentricity before the test, it is not adjusted according to the principle of complete alignment, but a certain deviation is reserved to compensate for the change in rotor concentricity under the influence of thermal expansion and deformation during the test, ensuring that the rotor is well aligned in the hot state. The most core link in this process is the estimation of the change in cold and hot concentricity. When designing a dual-axis compressor tester, it is usually symmetrical relative to the axis in the horizontal direction. Therefore, the influence of thermal expansion and deformation in the horizontal direction on concentricity is relatively small. This application is mainly aimed at the concentricity reservation in the vertical direction.

[0039] like Figure 2 As shown, the rotor concentricity reservation method of the dual-axis compressor tester with same-side input provided by the present application includes the following process:

[0040] S10, determining the thermal expansion displacement of the exhaust duct and the gearbox support structure in the height direction, and calculating the thermal expansion displacement of the input flange of the dual-axis compressor test piece and the output flange of the gearbox in the height direction based on the thermal expansion displacement and axial distance of the exhaust duct and the gearbox support structure in the height direction, thereby obtaining the estimated cold and hot concentricity change.

[0041] In the present application, the exhaust duct and gearbox support structure includes an exhaust duct front support, an exhaust duct rear support, a gearbox support front foot, and a gearbox support rear foot.

[0042] like Figure 3As shown, due to the baking of high-temperature exhaust during the test, the thermal expansion displacement of the exhaust duct rear support (point C) is usually larger than that of the exhaust duct front support (point A), and the thermal expansion displacement of the gearbox support front foot (point E) is larger than that of the gearbox support rear foot (point F). Therefore, the thermal expansion displacement of each point is calculated separately in this application, specifically including:

[0043] S11, obtaining temperature field data of the exhaust duct and the gearbox support structure through CFD simulation calculation, theoretical estimation, analogy analysis and other methods, where the temperature field data includes temperature variation.

[0044] S12, obtaining structural dimension data such as material, height, and axial distance of the exhaust duct and gearbox support structure according to the design drawings, and checking thermal expansion data such as thermal expansion coefficient of relevant materials under corresponding temperature field data.

[0045] S13, assuming that the biaxial compressor test piece and the exhaust duct undergo linear deformation during thermal expansion, calculate the thermal expansion displacement of the exhaust duct front support (point A) and the exhaust duct rear support (point C) in the height direction based on the temperature field data, structural dimension data, and thermal expansion data. 、 And the thermal expansion displacement of the gearbox support front foot and the gearbox support rear foot in the height direction 、 , where the thermal expansion displacement of the exhaust duct and gearbox support structure are calculated using the following formula:

[0046] ;

[0047] Where α is the thermal expansion coefficient of the material of the exhaust duct or gearbox support structure;

[0048] ΔT is the temperature change of the exhaust duct or gearbox support structure;

[0049] H Height of the exhaust duct or gearbox support structure.

[0050] Considering the large temperature difference between the gearbox base and the box body, a segmented calculation method is adopted; if the gradient of the exhaust duct support temperature field is large, a segmented calculation method should also be used to improve the calculation accuracy.

[0051] S14. Based on the calculation results of the thermal expansion displacement of the exhaust duct and gearbox support structure and the axial distance, the thermal expansion displacement of the input flange (point B) of the biaxial compressor test piece and the output flange (point D) of the gearbox in the height direction is calculated by linear interpolation, that is:

[0052] ;

[0053] ;

[0054] Where L is the axial distance.

[0055] The difference in thermal expansion displacement between the input flange (point B) of the dual-axis compressor test piece and the output flange (point D) of the gearbox represents the concentricity change during thermal expansion, and the estimated concentricity change in hot and cold states is: , it can be seen that when the parameters such as material thermal expansion coefficient α, support structure height H and axial distance L are determined, the change in concentricity is only related to the temperature change of the support structure, that is, .

[0056] S20, based on the estimated change in hot and cold concentricity , according to the thermal concentricity Estimated cold concentricity for standard calculations .

[0057] The rotor concentricity of the dual-axis compressor tester is adjusted based on the estimated cold concentricity. During cold concentricity adjustment, the gearbox height is typically adjusted using the dual-axis compressor test piece as a reference. Then, using the gearbox as a reference, the height of the power motor (not shown) inputting the gearbox on the same side is adjusted. It should be noted that vertical concentricity adjustment requires simultaneous consideration of horizontal alignment.

[0058] During the S30 test, vibration measurement points were placed at key locations of the biaxial compressor test piece, gearbox, and other equipment. At the same time, bearing temperature measurement points were placed at each support point in the biaxial compressor tester to monitor operating parameters such as vibration and bearing temperature at high speeds. In addition, in order to optimize the concentricity of the exhaust duct and the gearbox support structures, wall temperature measurement points were placed at each support position to obtain the temperature of each support structure during the test. .

[0059] If the operating performance is good, it indicates that the current hot concentricity will not generate additional vibration and the concentricity reservation plan is reasonable. If the operating performance is poor, an in-depth analysis of the measuring point data in the test is conducted to determine whether it is related to the hot alignment situation. If so, the concentricity reservation plan is optimized.

[0060] Among them, the concentricity reserve is corrected based on the measurement point data in the test to obtain the corrected reserved cold concentricity, specifically including:

[0061] S31, due to the residual heat of the supporting structures after the test, the concentricity will not return to the initial state immediately. The concentricity of the rotor of the biaxial compressor tester after the test can be obtained by timely inspection. , while recording the temperature of the exhaust duct and gearbox support structure after the test And other operating data.

[0062] Combined with the temperature of each support structure during the test , cold concentricity C estimated before the test, hot concentricity during the test Make an estimate to get the estimated hot concentricity of the test process ;

[0063] The actual concentricity change can be estimated: ;

[0064] S32, referring to step S14, re-evaluate and calculate the hot and cold concentricity variation based on the actual temperature (or temperature variation) of each support structure during the test, and obtain the hot and cold concentricity variation in the test , where It is the temperature change of the exhaust duct or gearbox support structure during the test.

[0065] S33, actual concentricity change estimated by comprehensive comparison And the change of concentricity in hot and cold states during the test The two calculation methods correct each other to reduce the influence of test data errors, structural nonlinear deformation and other factors, and obtain the corrected cold and hot concentricity change .

[0066] S34, finally repeat step S20, according to the hot concentricity As the standard, the cold concentricity is corrected and iterative verification is performed to obtain the corrected cold concentricity .

[0067] In response to the problem of significant concentricity changes caused by factors such as the short axial span of the exhaust duct support structure and high exhaust temperature of the dual-axis compressor tester, the present application comprehensively considers multiple influencing factors such as thermal expansion deformation of the exhaust duct support, thermal expansion deformation of the gearbox housing, thermal expansion deformation of the gearbox base, and uneven thermal expansion at different circumferential positions, thereby improving the calculation accuracy of the cold and hot state concentricity changes; at the same time, it proposes to correct the cold and hot state concentricity changes based on test data, so as to effectively reserve the rotor concentricity of the dual-axis compressor tester and effectively avoid abnormal phenomena such as shaft system vibration caused by poor hot concentricity.

[0068] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for reserving rotor concentricity of a biaxial compressor tester with same-side input, characterized in that: include: S10, determining the thermal expansion displacement in the height direction of the exhaust duct and gearbox support structure in the biaxial compressor tester with the same-side input, wherein the exhaust duct and gearbox support structure includes an exhaust duct front support, an exhaust duct rear support, and a gearbox support front leg and a gearbox support rear leg. Based on the thermal expansion displacement in the height direction and the axial distance of the exhaust duct and gearbox support structure, the thermal expansion displacement in the height direction of the input flange and the output flange of the gearbox of the biaxial compressor test piece are calculated, thereby obtaining an estimated concentricity change in the hot and cold states; S20, calculating an estimated cold concentricity based on the estimated change in cold and hot concentricity, with the hot concentricity being zero, and setting a rotor of the biaxial compressor tester based on the estimated cold concentricity; S30, arranging vibration measurement points, bearing temperature measurement points, and support structure wall temperature measurement points in the biaxial compressor tester, operating the biaxial compressor tester to perform a test, and determining an operating state of the biaxial compressor tester based on the vibration measurement points and the bearing temperature measurement points. If the operating state meets the requirements, then the estimated cold concentricity meets the requirements. If the operating state does not meet the requirements, the estimated cold concentricity is corrected using the data from the supporting structure wall temperature measurement points. The process includes: S31, obtain the concentricity of the rotor of the biaxial compressor tester after the test and the exhaust duct and gearbox support structure temperature T' after the test, and estimate the hot concentricity C" during the test based on the exhaust duct and gearbox support structure temperature T", the estimated cold concentricity C, and the concentricity C' after the test. cal1 =f(C,C',T',T'), and then the estimated actual concentricity change ΔC is obtained cal1 =C” cal1 -C; S32, re-evaluate and calculate the cold and hot concentricity variation based on the actual temperature of each support structure during the test, and obtain the cold and hot concentricity variation ΔC during the test. cal2 =f(α,H,L,ΔT”), ΔT” is the temperature change of the exhaust duct or gearbox support structure during the test; S33, by estimating the actual concentricity change ΔC cal1 And the change of concentricity in hot and cold states ΔC during the test cal2 Get the corrected cold and hot concentricity change ΔC corr ; S34, calculating the corrected cold concentricity based on the corrected change in the hot and cold concentricity, with the hot concentricity being zero.

2. The rotor concentricity reservation method for a biaxial compressor tester with same-side input according to claim 1, characterized in that: In step S10, the process of obtaining the estimated cold and hot concentricity variation includes: S11, acquiring temperature field data of the exhaust duct and the gearbox support structure, wherein the temperature field data includes temperature variation; S12, obtaining structural dimension data of the exhaust duct and the gearbox support structure, including material, height, and axial distance, and obtaining thermal expansion data of the material under corresponding temperature field data; S13, calculating the thermal expansion displacement ΔH of the exhaust duct front support and the exhaust duct rear support in the height direction based on the temperature field data, structural dimension data and thermal expansion data. A , ΔH C And the thermal expansion displacement ΔH of the gearbox support front foot and the gearbox support rear foot in the height direction E , ΔH F ; S14, based on the calculation results of the thermal expansion displacement of the exhaust duct and the gearbox support structure and the axial distance, the thermal expansion displacement of the input flange of the biaxial compressor test piece and the output flange of the gearbox in the height direction is calculated. The difference in the thermal expansion displacement of the input flange of the biaxial compressor test piece and the output flange of the gearbox is the concentricity change during the thermal expansion process, thereby obtaining an estimated cold and hot concentricity change of ΔC = ΔH B -ΔH D , where ΔH B , ΔH D They are the thermal expansion displacements of the input flange of the dual-shaft compressor test piece and the output flange of the gearbox.

3. The rotor concentricity reservation method for a biaxial compressor tester with same-side input according to claim 2, characterized in that: The temperature field data of the exhaust duct and gearbox support structure temperature changes are obtained through CFD simulation calculation, theoretical estimation, and analogy analysis methods.

4. The rotor concentricity reservation method for a biaxial compressor tester with same-side input according to claim 2, characterized in that: The thermal expansion displacement ΔH of the exhaust duct front support and the exhaust duct rear support in the height direction A , ΔH C And the thermal expansion displacement ΔH of the gearbox support front foot and the gearbox support rear foot in the height direction E , ΔH F The calculation method is: ΔH=α×H×ΔT Where α is the thermal expansion coefficient of the material of the exhaust duct or gearbox support structure; ΔT is the temperature change of the exhaust duct or gearbox support structure; H is the height of the exhaust duct or gearbox support structure.

5. The rotor concentricity reservation method for a biaxial compressor tester with same-side input according to claim 4, characterized in that: The thermal expansion displacement of the input flange of the biaxial compressor test piece and the output flange of the gearbox in the height direction is calculated by linear interpolation method, namely: ΔH B =f(ΔH A ,ΔH C ,L) ΔH D =f(ΔH E ,ΔH F ,L) Where L is the axial distance.

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