Centrifugal impeller monitoring method and system based on twin reduced-order model

Abstract

The invention relates to the technical field of operation state monitoring of large rotating mechanical equipment, and particularly provides a centrifugal impeller monitoring method and system based on a twin reduced-order model.The centrifugal impeller is provided with all-round blades, and the monitoring method comprises the steps that blade tip vibration signals of the all-round blades are collected to obtain original vibration data; preprocessing the original vibration data to obtain blade tip vibration data; processing the blade tip vibration data based on a keyless phase reference method to obtain blade tip vibration displacement; carrying out nonlinear least square curve fitting on the blade tip vibration displacement, and identifying kinetic parameters of each independent blade in the blades of the whole circumference; constructing a twinning reduced-order model of the centrifugal impeller, and determining update parameters of the twinning reduced-order model based on the kinetic parameters; updating the twin reduced-order model based on the update parameters to obtain a digital model; and monitoring the centrifugal impeller based on the digital model. According to the method, the response calculation load is relatively small, the detuning parameters are relatively easy to extract, and the real-time performance and the accuracy are relatively high.

Description

Technical Field

[0001] The present invention relates to the technical field of operation status monitoring and diagnosis and maintenance of large-scale rotating mechanical equipment, and in particular to a centrifugal impeller monitoring method and system based on a twin reduced-order model. Background Art

[0002] Centrifugal compressors have the advantages of high single-stage pressure ratio, wide operating range, and compact structure. They are core power equipment in important fields such as petrochemicals, natural gas, coal chemical industry, and aerospace, and they occupy a very important position in the national economy and national defense construction.

[0003] In recent years, dozens of centrifugal compressor impeller failures have occurred at home and abroad, resulting in blades vibrating excessively and breaking, causing huge economic losses and serious social impacts to enterprises. According to public reports and failure statistics analysis at home and abroad, the vast majority of centrifugal impeller failures are caused by impeller vibration and high-cycle fatigue damage caused by unsteady fluid excitation. As the core working component of a centrifugal compressor, the centrifugal impeller often operates under high tip tangential speed and high aerodynamic load conditions. With the improvement of aerodynamic design parameters, the unsteady loads and pulsating airflows carried by the centrifugal impeller continue to intensify, resulting in frequent impeller fatigue failures.

[0004] The online monitoring method can monitor the vibration response of the blade in real time, but the vibration at the tip or a point on the blade surface is difficult to fully reflect the overall response of the centrifugal impeller; affected by processing errors and operational wear, the centrifugal impeller will inevitably be detuned. The destruction of the cyclic symmetry characteristics of the structure will have an adverse effect on the vibration of the blade, and for specific detuning forms and aerodynamic load conditions, the vibration response may change dramatically, and the initial model is no longer suitable for centrifugal impeller entities that have been in service for a long time. The existing twin models for centrifugal impeller health monitoring have problems such as large response calculation load, difficult extraction of detuning parameters, and lack of linkage mechanism for digital models. It is difficult to meet the monitoring needs of centrifugal impeller operation and maintenance diagnosis, online fatigue assessment, etc. Summary of the invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problems of large response calculation load, difficult extraction of detuning parameters and lack of linkage mechanism in the twin model used to monitor centrifugal impellers in the prior art, and provide a centrifugal impeller monitoring method and system based on the twin reduced-order model, which has a linkage mechanism, small response calculation load, easy extraction of detuning parameters, and high real-time and accuracy.

[0006] In a first aspect, in order to solve the above technical problems, the present invention provides a centrifugal impeller monitoring method based on a twin reduced-order model, wherein the centrifugal impeller is equipped with full-circumference blades, and the monitoring method comprises the following steps:

[0007] Collecting the blade tip vibration signal of the full-circumference blade to obtain original vibration data;

[0008] Preprocessing the original vibration data to obtain blade tip vibration data;

[0009] Processing the blade tip vibration data based on a keyless phase reference method to obtain a blade tip vibration displacement;

[0010] Performing nonlinear least square curve fitting on the blade tip vibration displacement to identify the dynamic parameters of each independent blade in the full-circumference blade;

[0011] Constructing a twin reduced-order model of the centrifugal impeller, and determining update parameters of the twin reduced-order model based on the dynamic parameters;

[0012] Updating the twin reduced-order model based on the update parameters to obtain a digital model;

[0013] Monitoring the centrifugal impeller based on the digital model; The step of constructing the twin reduced-order model of the centrifugal impeller includes: The centrifugal impeller is divided into a first substructure and a second substructure by using a mixed interface method: The first substructure corresponds to an integrally coordinated impeller, and a model of the first substructure is generated using a coordinated mode in a harmonic nominal mode subset; The second substructure corresponds to a detuned blade, and a model of the second substructure introduces a mass detuned model or a stiffness detuned model; A twin reduced-order model of the centrifugal impeller is constructed based on the model of the first substructure and the model of the second substructure.

[0014] In one embodiment of the present invention, collecting the blade tip vibration signal of the full-circumference blade to obtain the original vibration data includes the following steps:

[0015] Using the block Lanczos method to perform modal analysis on the centrifugal impeller to obtain the impeller mode;

[0016] Based on the impeller mode, a blade tip timing sensor is installed in the circumferential direction of the end wall casing of the centrifugal impeller;

[0017] The blade tip vibration signal of the full-circumference blade is collected based on the blade tip timing sensor to obtain original vibration data.

[0018] In one embodiment of the present invention, preprocessing the raw vibration data to obtain blade tip vibration data comprises the following steps:

[0019] First, the initialization frequency parameter is obtained based on the first m blade tip pulse count sequences in the original vibration data. :

[0020] ;

[0021] in, is the j-th blade tip pulse counting sequence, is the j-1th blade tip pulse counting sequence, is the counter base frequency;

[0022] Then, calculate the theoretical pulse count interval :

[0023] ;

[0024] in, The number of blade tip timing sensors;

[0025] Next, based on the actual pulse count interval of blade tip vibration Get blade tip vibration data, the actual pulse count interval Need to meet:

[0026] .

[0027] In one embodiment of the present invention, the blade tip vibration data is processed based on the keyless phase reference method to obtain the blade tip vibration displacement, comprising the following steps:

[0028] converting the blade tip vibration data into a blade tip arrival timing sequence;

[0029] determining a timing reference signal based on the blade tip arrival timing sequence;

[0030] Calculate the rotation period and rotation frequency corresponding to each rotation of the centrifugal impeller based on the timing reference signal;

[0031] Obtaining an ideal arrival time based on the rotation period or the rotation frequency;

[0032] The blade tip vibration displacement is obtained based on the ideal arrival time.

[0033] In one embodiment of the present invention, the step of constructing the twin reduced-order model of the centrifugal impeller comprises:

[0034] Based on the dynamic parameters, update parameters of the twin reduced-order model are determined, wherein the update parameters include a damping ratio. The steps include:

[0035] The damping matrix of each independent blade of the centrifugal impeller is constructed using the Rayleigh damping model. :

[0036] ;

[0037] The constant mass damping coefficient is set to zero so that the damping matrix With the mass matrix Regardless, the damping matrix Only with the harmonic stiffness matrix Proportional; constant stiffness damping coefficient for:

[0038] ;

[0039] in, is the angular frequency corresponding to the resonant speed of the centrifugal impeller, is the damping ratio of each independent blade of the centrifugal impeller.

[0040] In one embodiment of the present invention, based on the dynamic parameters, the update parameters of the twin reduced-order model are determined, and the update parameters include a detuning deviation. The steps include:

[0041] ;

[0042] in, is the natural frequency of blade k, For ideally tuned blade frequency.

[0043] In one embodiment of the present invention, the step of updating the twin reduced-order model based on the update parameter includes:

[0044] The update of the twin reduced-order model is regarded as a decision problem, and the correction criterion of the decision problem is:

[0045] ;

[0046] ;

[0047] in, Indicates the overall deviation degree of the parameter group of the single dynamic parameter of each independent blade; represents a pulse index, and the pulse index is used to evaluate the maximum deviation degree of the single kinetic parameter; The number of blade tip timing sensors; is the first determination threshold; is the second determination threshold; represents the update parameters of the twin reduced-order model; Represents the update parameters with The corresponding kinetic parameter identification results; Σ represents the sum; ‖ represents the absolute value.

[0048] In one embodiment of the present invention, the step of monitoring the centrifugal impeller based on the digital model comprises:

[0049] Calculating a three-dimensional response field based on the digital model;

[0050] Introducing cyclic coordinates into the three-dimensional response field, and transforming the cyclic coordinates into physical coordinates to obtain a motion equation;

[0051] Obtaining a modal participation factor of each independent blade based on the motion equation;

[0052] The state index of the centrifugal impeller is characterized based on the modal participation factor, and the state index includes three-dimensional full-field vibration displacement and strain; when the state index is within a set range, the monitoring result of the centrifugal impeller is normal; when the state index is not within the set range, the monitoring result of the centrifugal impeller is abnormal.

[0053] In a second aspect, in order to solve the above technical problems, the present invention further provides a centrifugal impeller monitoring system based on a twin reduced-order model, wherein the centrifugal impeller is equipped with full-circumference blades, and the monitoring system comprises:

[0054] A collection module collects the tip vibration signal of the full-circle blade to obtain original vibration data;

[0055] A first processing module pre-processes the original vibration data to obtain blade tip vibration data;

[0056] A second processing module processes the blade tip vibration data based on a keyless phase reference method to obtain a blade tip vibration displacement;

[0057] A parameter identification module performs nonlinear least square curve fitting on the blade tip vibration displacement to identify the dynamic parameters of each independent blade in the full-circumference blade;

[0058] A model building module, constructing a twin reduced-order model of the centrifugal impeller, and determining update parameters of the twin reduced-order model based on the dynamic parameters;

[0059] A model updating module, which updates the twin reduced-order model based on the update parameters to obtain a digital model;

[0060] A monitoring module, for monitoring the centrifugal impeller based on the digital model;

[0061] The step of constructing the twin reduced-order model of the centrifugal impeller includes: The centrifugal impeller is divided into a first substructure and a second substructure by using a mixed interface method: The first substructure corresponds to an integrally coordinated impeller, and a model of the first substructure is generated using a coordinated mode in a harmonic nominal mode subset; The second substructure corresponds to a detuned blade, and a model of the second substructure introduces a mass detuned model or a stiffness detuned model; A twin reduced-order model of the centrifugal impeller is constructed based on the model of the first substructure and the model of the second substructure.

[0062] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0063] The present invention provides a centrifugal impeller monitoring method and system based on a twin reduced-order model. The update parameters of the twin reduced-order model are determined based on dynamic parameters, and a virtual-real interactive parameter fusion mechanism is established to achieve the coupling linkage between the blade tip vibration signal and the twin reduced-order model. The response calculation load is small, the detuning parameters are relatively easy to extract, and the real-time performance and accuracy are high. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0065] Figure 1 A flow chart of the steps of a centrifugal impeller monitoring method based on a twin reduced-order model in a preferred embodiment of the present invention;

[0066] Figure 2 A schematic diagram of a pulse signal of raw vibration data that has not been preprocessed in a preferred embodiment of the present invention;

[0067] Figure 3 A schematic diagram of a pulse signal of blade tip vibration data obtained by preprocessing in a preferred embodiment of the present invention;

[0068] Figure 4 It is a schematic diagram of the calculation result of the tip vibration displacement of blade No. 11 in the preferred embodiment of the present invention;

[0069] Figure 5 It is a schematic diagram of the frequency identification results of each independent blade in the preferred embodiment of the present invention;

[0070] Figure 6 It is a schematic diagram of the fitting results of blade No. 3 and blade No. 12 in the preferred embodiment of the present invention;

[0071] Figure 7 A schematic diagram of a twin reduced-order model of a centrifugal impeller in a preferred embodiment of the present invention;

[0072] Figure 8 The present invention is a flowchart of a centrifugal impeller monitoring system based on a twin reduced-order model in an embodiment of the present invention. DETAILED DESCRIPTION

[0073] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0074] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0075] In the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0076] The online monitoring method can monitor the vibration response of the blade in real time, but the vibration at the tip or a point on the blade surface is difficult to fully reflect the overall response of the centrifugal impeller; affected by processing errors and operational wear, the centrifugal impeller will inevitably be detuned. The destruction of the cyclic symmetry characteristics of the structure will have an adverse effect on the vibration of the blade, and for specific detuning forms and aerodynamic load conditions, the vibration response may change dramatically, and the initial model is no longer suitable for centrifugal impeller entities that have been in service for a long time. The existing twin models for centrifugal impeller health monitoring have problems such as large response calculation load, difficult extraction of detuning parameters, and lack of linkage mechanism for digital models. It is difficult to meet the monitoring needs of centrifugal impeller operation and maintenance diagnosis, online fatigue assessment, etc.

[0077] The inventors of this application have considered that online monitoring and operation and maintenance evaluation of centrifugal impellers belong to the problems of real-time updating and digital-analog linkage, and the virtual-real fusion method can provide a solution for the accurate evaluation of the vibration response of centrifugal impellers and the early warning of dangerous failure parts. However, due to the limitation of the number of channels, strain testing is difficult to fully identify and obtain the vibration response parameters of the detuned impeller. At the same time, the additional strain will also have an impact on the actual structural dynamics system. For this reason, non-contact vibration measurement technology is chosen, such as using blade tip timing sensors to obtain the vibration signals of the blades around the entire circumference; then the dynamic parameters are identified, and then updated in linkage with the twin reduced-order model to establish a virtual-real interactive parameter fusion mechanism.

[0078] Therefore, an embodiment of the present application provides a centrifugal impeller monitoring method and system based on a twin reduced-order model.

[0079] Embodiment 1

[0080] This embodiment provides a centrifugal impeller monitoring method based on a twin reduced-order model. The centrifugal impeller is equipped with full-circumference blades. Please refer to Figure 1As shown, including:

[0081] Step S1, collecting the blade tip vibration signal of the full-circumference blade to obtain original vibration data;

[0082] Step S2, preprocessing the original vibration data to obtain blade tip vibration data;

[0083] Step S3, processing the blade tip vibration data based on a keyless phase reference method to obtain a blade tip vibration displacement;

[0084] Step S4, performing nonlinear least square curve fitting on the blade tip vibration displacement to identify the dynamic parameters of each independent blade in the full-circumference blade;

[0085] Step S5, constructing a twin reduced-order model of the centrifugal impeller, and determining update parameters of the twin reduced-order model based on the dynamic parameters;

[0086] Step S6, updating the twin reduced-order model based on the update parameters to obtain a digital model;

[0087] Step S7, monitoring the centrifugal impeller based on the digital model; The step of constructing the twin reduced-order model of the centrifugal impeller includes: The centrifugal impeller is divided into a first substructure and a second substructure by using a mixed interface method: The first substructure corresponds to an integrally coordinated impeller, and a model of the first substructure is generated using a coordinated mode in a harmonic nominal mode subset; The second substructure corresponds to a detuned blade, and a model of the second substructure introduces a mass detuned model or a stiffness detuned model; A twin reduced-order model of the centrifugal impeller is constructed based on the model of the first substructure and the model of the second substructure.

[0088] The present embodiment provides a centrifugal impeller monitoring method based on a twin reduced-order model. (1) The update parameters of the twin reduced-order model are determined based on the dynamic parameters, and a virtual-real interactive parameter fusion mechanism is established to achieve the coupling linkage between the blade tip vibration signal and the twin reduced-order model, thereby improving the consistency between the physical entity and the twin reduced-order model. (2) The response calculation load is small, the detuning parameters are relatively easy to extract, and the real-time performance and accuracy are relatively high. The method can be applied to the full-field online monitoring and fatigue assessment of high-speed centrifugal impeller dynamics.

[0089] Next, a centrifugal impeller monitoring method based on a twin reduced-order model provided in this embodiment is introduced in detail:

[0090] Specifically, the centrifugal impeller is configured with full-circumference blades.

[0091] Among them, "full-circumference blades" means that the blades on the centrifugal impeller are evenly distributed around the hub, covering the entire circumference of the centrifugal impeller.

[0092] Step S1: collecting the blade tip vibration signal of the full-circumference blade to obtain original vibration data.

[0093] Specifically, selecting blade tip vibration signals with significant modal vibration for monitoring can improve signal quality.

[0094] Step S101, using a block Lanczos method to perform modal analysis on the centrifugal impeller to obtain an impeller mode;

[0095] Optionally, the impeller modes include blade tip modal displacement and modal strain field.

[0096] Step S102, installing a blade tip timing sensor in the circumferential direction of the end wall casing of the centrifugal impeller based on the impeller mode;

[0097] Optionally, there are one or more blade tip timing sensors; the blade tip timing sensor is installed on the channel cover side of the centrifugal impeller and is flush with the wall surface; the base frequency of the counter acquisition card of the blade tip timing sensor is set to 80 MHz.

[0098] Step S103 : collecting the blade tip vibration signal of the full-circumference blade based on the blade tip timing sensor to obtain original vibration data.

[0099] Optionally, a laser emission box is used to provide a laser light source for measurement.

[0100] When each independent blade in the above-mentioned full-circumference blade rotates through the above-mentioned blade tip timing sensor, the blade top surface of each independent blade dynamically reflects the laser, and the blade tip vibration signal of each independent blade is fed back to the acquisition module of the above-mentioned blade tip timing sensor in real time in the form of a trigger pulse, and the counter acquisition card of the above-mentioned blade tip timing sensor then obtains the arrival timing of each independent blade.

[0101] Step S2: pre-processing the original vibration data to obtain blade tip vibration data.

[0102] Step S201, obtaining the initialization frequency parameter according to the first m blade tip pulse count sequences in the original vibration data :

[0103] ;

[0104] in, is the j-th blade tip pulse counting sequence, is the j-1th blade tip pulse counting sequence, is the counter base frequency, Indicates sum.

[0105] At the same time, it is necessary to verify the above initialization frequency conversion parameters Is it within the normal operating speed range of the centrifugal impeller?

[0106] In satisfying In the case of Within the normal operating speed range of the centrifugal impeller; In the case of If the centrifugal impeller is not within the normal operating speed range, it is necessary to search backward along the above m tip pulse counting sequence until the condition is satisfied. Initialization frequency conversion parameters ;in, is the lowest value of the set frequency. The maximum value of the set frequency.

[0107] Step S202, taking into account the timing pulse intervals of the above-mentioned independent blades when they are not vibrating, calculate the theoretical pulse counting interval :

[0108] ;

[0109] in, The number of blade tip timing sensors mentioned above.

[0110] Step S203, based on the actual pulse counting interval of blade tip vibration Get blade tip vibration data, the actual pulse count interval Need to meet:

[0111] ;

[0112] Specifically, the blade tip vibration data obtained thereby can reduce the influence of abnormal pulses and interference noise.

[0113] For example, a semi-open centrifugal impeller with 19 independent blades is used as the monitoring object. The test results without the above pretreatment under high speed and high pressure working environment are shown in Figure 2 As shown, the irregular black vertical line on the vertical axis indicates the influence of abnormal pulse and noise interference; please refer to the test results obtained after the above preprocessing Figure 3 shown.

[0114] It can be seen that compared with the original vibration data without the above preprocessing, the blade tip vibration data obtained by the above preprocessing is more accurate and effective.

[0115] Step S3: Processing the blade tip vibration data based on the keyless phase reference method to obtain the blade tip vibration displacement.

[0116] Affected by the end wall casing processing error, blade tip timing sensor installation positioning error, etc., the interval angle of each independent blade has deviations, and the key phase signal needs to be used as a vibration-free reference in the vibration solution process. However, in practice, it is difficult to install key phase sensors on large energy equipment. Even if the above key phase sensors are installed, the key phase sensors are easily affected by the vibration of the base, which will bring large errors to the amplitude calculation of each independent blade.

[0117] Therefore, the embodiment of the present application uses a keyless phase reference method to process the blade tip vibration data:

[0118] Step S301, converting the blade tip vibration data into a blade tip arrival timing sequence.

[0119] Specifically, read the tip pulse count sequence obtained by the counter acquisition card , then based on the above counter base frequency Convert it into a blade tip arrival timing sequence ;

[0120] Among them, k represents the kth blade in each independent blade, i represents the i-th blade tip timing sensor, and n represents the nth revolution of the centrifugal impeller.

[0121] Step S302: determining a timing reference signal based on the blade tip arrival timing sequence.

[0122] Specifically, the timing reference signal and They are:

[0123] ;

[0124] Step S303: Calculate the rotation period and rotation frequency corresponding to each rotation of the centrifugal impeller based on the timing reference signal.

[0125] Specifically, the rotation period corresponding to each rotation of the centrifugal impeller is and frequency conversion They are:

[0126] .

[0127] Step S304: obtaining an ideal arrival time based on the rotation period or the rotation frequency.

[0128] Specifically, the ideal arrival time of each individual blade is for:

[0129] ;

[0130] in, Indicates the number of revolutions the centrifugal impeller has made.

[0131] Step S305: obtaining the blade tip vibration displacement based on the ideal arrival time.

[0132] Specifically, the blade tip vibration displacement for:

[0133] ;

[0134] in, is the rotational angular frequency of the centrifugal impeller, is the radius of gyration at the tip of the centrifugal impeller, is the ratio of pi.

[0135] For example, the semi-open centrifugal impeller with 19 independent blades is used as the monitoring object, and the vibration amplitude of the 11th blade of the centrifugal impeller is used as an example. The tip vibration displacement solution obtained by the keyless phase reference method is shown in FIG. Figure 4 shown.

[0136] Step S4: performing nonlinear least square curve fitting on the blade tip vibration displacement to identify the dynamic parameters of each independent blade in the full-circumference blade.

[0137] Optionally, a Levenberg-Marquardt algorithm is used for nonlinear least squares curve fitting.

[0138] Specifically, the dynamic parameters of each independent blade include the natural frequency , displacement amplitude , Phase , Damping ratio , constant C, resonance order .

[0139] Under under-sampling conditions, the dynamic parameter equation of each independent blade is:

[0140] ;

[0141] ;

[0142] ;

[0143] ;

[0144] in, is the frequency, is the quality factor, To calculate the intermediate variables, is the installation interval angle of the blade tip timing sensor, is the initial phase.

[0145] For example, the above-mentioned semi-open centrifugal impeller with 19 independent blades is used as the monitoring object, and the above-mentioned nonlinear least squares curve fitting is performed. Taking the frequency as an example, the frequency identification results of each independent blade can be found in Figure 5 shown.

[0146] For example, please refer to Figure 6 As shown in the figure, taking the 3rd and 12th blades of the centrifugal impeller as examples, the fitting waveform of the normalized tip amplitude has good consistency with the original point set, so the dynamic parameters identified based on this will be more accurate; among them, represents the instantaneous rotation speed of the centrifugal impeller, Indicates the maximum rotation speed of the above centrifugal impeller.

[0147] Step S5: constructing a twin reduced-order model of the centrifugal impeller, and determining update parameters of the twin reduced-order model based on the dynamic parameters.

[0148] Step S501, constructing a twin reduced-order model of the centrifugal impeller:

[0149] Preferably, a hybrid interface method is used to divide the centrifugal impeller into a first substructure and a second substructure to achieve "order reduction" of the existing twin model;

[0150] The first substructure corresponds to an integrally coordinated impeller, and a model of the first substructure is generated using a coordinated mode in a harmonic nominal mode subset (Subset of Nominal Modes, SNM for short);

[0151] The second substructure corresponds to a detuned blade, and a model of the second substructure introduces a mass detuned model or a stiffness detuned model;

[0152] A twin reduced-order model of the centrifugal impeller is constructed based on the model of the first substructure and the model of the second substructure.

[0153] Preferably, a stiffness detuning model is introduced Construct a model of the second substructure above:

[0154] ;

[0155] in, represents the coordination stiffness matrix, represents the detuned stiffness.

[0156] Furthermore, the Rayleigh damping model is used to construct the damping matrix of each independent blade of the centrifugal impeller. :

[0157] ;

[0158] The constant mass damping coefficient is set to zero so that the damping matrix With the mass matrix Regardless, the damping matrix Only with the harmonic stiffness matrix Proportional; constant stiffness damping coefficient for:

[0159] ;

[0160] in, is the angular frequency corresponding to the resonant speed of the centrifugal impeller.

[0161] Furthermore, the regular mode set normalized by mass matrix The modal coordinate transformation is performed on the coordinated impeller corresponding to the first substructure to obtain the detuned centrifugal impeller twin reduced-order model:

[0162] ;

[0163] in, is the angular frequency, is the identity matrix, is a unit plural, is the generalized stiffness matrix of the above tuned impeller system, is the displacement of the modal coordinate system, is the load of the centrifugal impeller, Indicates transpose.

[0164] Furthermore, the cantilever blade canonical modes based on the Craig-Bampton method are used for mapping, and the detuning term It can be expressed as:

[0165] ;

[0166] ;

[0167] ;

[0168] in, is the number of independent blades of the above centrifugal impeller, is a diagonal matrix function, is the modal participation factor of blade k; detuning parameter , represents the rth main modal frequency deviation of the kth blade.

[0169] Furthermore, ignoring the coupling between modes and boundary effects, the above detuned centrifugal impeller twin reduced-order model can be simplified to:

[0170] ;

[0171] in, Main modal set.

[0172] For example, the centrifugal impeller twin reduced-order model constructed by the above steps can be found in Figure 7 As shown, the second substructure includes 19 independent blades, which are evenly arranged on the first substructure.

[0173] Step S502, determining update parameters of the twin reduced-order model based on the dynamic parameters:

[0174] Preferably, the update parameter includes a detuning deviation. Corresponding to the above detuning parameters , determine the detuning deviation The steps include:

[0175] First, the detuning parameters are determined based on the dynamic parameter identification results of each independent blade. ;

[0176] Furthermore, the proportional detuning is quantified by the elastic modulus perturbation:

[0177] ;

[0178] in, is the equivalent elastic modulus of the kth blade, and the detuning coefficient of the kth blade is To update the nominal elastic modulus of each independent blade , so that the natural frequency parameters of each independent blade are Make corrections.

[0179] Therefore, the stiffness of blade k is detuned It can be expressed as:

[0180] ;

[0181] in, is the nominal stiffness matrix.

[0182] Furthermore, for the above detuning parameters To simplify:

[0183] ;

[0184] Furthermore, the detuning deviation is introduced To express :

[0185] ;

[0186] Among them, the detuning deviation dimensionless, is the natural frequency of blade k, For ideally tuned blade frequency.

[0187] Through the above steps, the detuning parameters can be extracted relatively easily, thereby improving the real-time performance and accuracy.

[0188] Step S6: Update the twin reduced-order model based on the update parameters to obtain a digital model.

[0189] Preferably, the update of the twin reduced-order model is regarded as a decision problem, and the correction criterion of the decision problem is:

[0190] ;

[0191] ;

[0192] in, It represents the overall deviation degree of the parameter group of the single dynamic parameters of each independent blade mentioned above; represents a pulse index, which is used to evaluate the maximum deviation degree of a single dynamic parameter of each independent blade; The number of blade tip timing sensors; is the first determination threshold; is the second determination threshold; represents the update parameters of the twin reduced-order model; Represents the update parameters with The corresponding kinetic parameter identification results; Σ represents the sum; ‖ represents the absolute value.

[0193] Preferably, the above update parameters is the damping ratio or detuning deviation .

[0194] Specifically, the twin reduced-order model of the centrifugal impeller is updated through the above steps, a virtual-real interactive parameter fusion mechanism is established, and the coupling and linkage between the blade tip vibration signal and the twin reduced-order model is realized, thereby obtaining a digital model consistent with the physical entity.

[0195] Step S7: monitoring the centrifugal impeller based on the digital model.

[0196] Step S701, calculating and obtaining a three-dimensional response field based on the digital model.

[0197] Because the digital model is consistent with the physical entity, the three-dimensional response field is consistent with the actual collected blade tip vibration displacement.

[0198] Step S702, introducing cyclic coordinates into the three-dimensional response field, and transforming the cyclic coordinates into physical coordinates to obtain a motion equation;

[0199] Specifically, from the cycle coordinates To physical coordinates The transformation is:

[0200] ;

[0201] in, is a real-valued Fourier matrix, is the direct product operator.

[0202] Specifically, the above equation of motion is: ;

[0203] in, represents a pseudo-block diagonal matrix, is the impeller pitch diameter harmonic number set of the centrifugal impeller, The harmonic number is The real-valued circular main mode set at .

[0204] Step S703, obtaining a modal participation factor of each independent blade based on the motion equation;

[0205] Specifically, the harmonic number is When , the participation factor of each independent blade in the cyclic symmetric mode is for:

[0206] ;

[0207] represents the real-valued circular principal mode set The leaf part in the

[0208] is the generalized stiffness matrix of the cantilever blade;

[0209] is the nominal stiffness matrix of the above cantilever blade;

[0210] Main modal set.

[0211] Furthermore, the modal participation factor of each independent blade is for:

[0212] ;

[0213] in, is the real-valued Fourier matrix The kth row in .

[0214] Step S704: based on the modal participation factor The state indicators of the centrifugal impeller are characterized, and the state indicators include three-dimensional full-field vibration displacement and strain; when the state indicators are within the set range, the monitoring result of the centrifugal impeller is normal; when the state indicators are not within the set range, the monitoring result of the centrifugal impeller is abnormal.

[0215] Specifically, when the monitoring result of the centrifugal impeller is abnormal, it indicates that the centrifugal impeller faces the risk of fatigue failure.

[0216] By monitoring the centrifugal impeller through the above steps, the response calculation load can be reduced and the real-time performance and accuracy can be improved.

[0217] Embodiment 2

[0218] This embodiment provides a centrifugal impeller monitoring system based on a twin reduced-order model. The centrifugal impeller is equipped with full-circumference blades. Please refer to Figure 8 As shown, including:

[0219] The acquisition module 100 acquires the blade tip vibration signal of the full-circumference blade to obtain original vibration data;

[0220] A first processing module 200 pre-processes the original vibration data to obtain blade tip vibration data;

[0221] A second processing module 300 processes the blade tip vibration data based on a keyless phase reference method to obtain a blade tip vibration displacement;

[0222] A parameter identification module 400 performs nonlinear least square curve fitting on the blade tip vibration displacement to identify the dynamic parameters of each independent blade in the full-circumference blade;

[0223] A model building module 500 is used to build a twin reduced-order model of the centrifugal impeller and determine update parameters of the twin reduced-order model based on the dynamic parameters;

[0224] A model updating module 600 updates the twin reduced-order model based on the update parameters to obtain a digital model;

[0225] A monitoring module 700, for monitoring the centrifugal impeller based on the digital model; The step of constructing the twin reduced-order model of the centrifugal impeller includes: The centrifugal impeller is divided into a first substructure and a second substructure by using a mixed interface method: The first substructure corresponds to an integrally coordinated impeller, and a model of the first substructure is generated using a coordinated mode in a harmonic nominal mode subset; The second substructure corresponds to a detuned blade, and a model of the second substructure introduces a mass detuned model or a stiffness detuned model; A twin reduced-order model of the centrifugal impeller is constructed based on the model of the first substructure and the model of the second substructure.

[0226] For an introduction to a centrifugal impeller monitoring system based on a twin reduced-order model provided in this embodiment, please refer to Embodiment 1, and this embodiment will not be described in detail here.

[0227] The centrifugal impeller monitoring system based on the twin reduced-order model provided in this embodiment has the same beneficial effects as the centrifugal impeller monitoring method based on the twin reduced-order model described above.

[0228] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0229] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0230] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0231] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0232] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A centrifugal impeller monitoring method based on a twin reduced-order model, wherein the centrifugal impeller is equipped with full-circumference blades, characterized in that: The monitoring method comprises the following steps: Collecting the blade tip vibration signal of the full-circumference blade to obtain original vibration data; Preprocessing the original vibration data to obtain blade tip vibration data; Processing the blade tip vibration data based on a keyless phase reference method to obtain a blade tip vibration displacement; Performing nonlinear least square curve fitting on the blade tip vibration displacement to identify the dynamic parameters of each independent blade in the full-circumference blade; Constructing a twin reduced-order model of the centrifugal impeller, and determining update parameters of the twin reduced-order model based on the dynamic parameters; Updating the twin reduced-order model based on the update parameters to obtain a digital model; Monitoring the centrifugal impeller based on the digital model; The step of constructing the twin reduced-order model of the centrifugal impeller includes: The centrifugal impeller is divided into a first substructure and a second substructure by using a mixed interface method: The first substructure corresponds to an integrally coordinated impeller, and a model of the first substructure is generated using a coordinated mode in a harmonic nominal mode subset; The second substructure corresponds to a detuned blade, and a model of the second substructure introduces a mass detuned model or a stiffness detuned model; A twin reduced-order model of the centrifugal impeller is constructed based on the model of the first substructure and the model of the second substructure.

2. A centrifugal impeller monitoring method based on twin reduced-order model according to claim 1, characterized in that: Collecting the blade tip vibration signal of the full-circumference blade to obtain original vibration data includes the following steps: Using the block Lanczos method to perform modal analysis on the centrifugal impeller to obtain the impeller mode; Based on the impeller mode, a blade tip timing sensor is installed in the circumferential direction of the end wall casing of the centrifugal impeller; The blade tip vibration signal of the full-circumference blade is collected based on the blade tip timing sensor to obtain original vibration data.

3. The centrifugal impeller monitoring method based on twin reduced-order model according to claim 1, characterized in that: Preprocessing the raw vibration data to obtain blade tip vibration data comprises the following steps: First, the initialization frequency parameter is obtained based on the first m blade tip pulse count sequences in the original vibration data. : ； in, is the j-th blade tip pulse counting sequence, is the j-1th blade tip pulse counting sequence, is the counter base frequency, It means sum; Then, calculate the theoretical pulse count interval : ； in, The number of blade tip timing sensors; Next, based on the actual pulse count interval of blade tip vibration Get blade tip vibration data, the actual pulse count interval Need to meet: 。 4. The centrifugal impeller monitoring method based on twin reduced-order model according to claim 1, characterized in that: Processing the blade tip vibration data based on the keyless phase reference method to obtain the blade tip vibration displacement includes the following steps: converting the blade tip vibration data into a blade tip arrival timing sequence; determining a timing reference signal based on the blade tip arrival timing sequence; Calculate the rotation period and rotation frequency corresponding to each rotation of the centrifugal impeller based on the timing reference signal; Obtaining an ideal arrival time based on the rotation period or the rotation frequency; The blade tip vibration displacement is obtained based on the ideal arrival time.

5. The centrifugal impeller monitoring method based on twin reduced-order model according to claim 1, characterized in that: The steps of constructing the twin reduced-order model of the centrifugal impeller include: The damping matrix of each independent blade of the centrifugal impeller is constructed using the Rayleigh damping model. : ； The constant mass damping coefficient is set to zero so that the damping matrix With the mass matrix Regardless, the damping matrix Only with the harmonic stiffness matrix Proportional; constant stiffness damping coefficient for: ； in, is the angular frequency corresponding to the resonant speed of the centrifugal impeller, is the damping ratio of each independent blade of the centrifugal impeller.

6. The centrifugal impeller monitoring method based on twin reduced-order model according to claim 1, characterized in that: Based on the dynamic parameters, update parameters of the twin reduced-order model are determined, wherein the update parameters include a detuning deviation, and the detuning deviation is determined. The steps include: ； in, is the natural frequency of blade k, For ideally tuned blade frequency.

7. The centrifugal impeller monitoring method based on twin reduced-order model according to claim 1, characterized in that: The step of updating the twin reduced-order model based on the update parameter comprises: The update of the twin reduced-order model is regarded as a decision problem, and the correction criterion of the decision problem is: ； ； in, Indicates the overall deviation degree of the parameter group of the single dynamic parameter of each independent blade; represents a pulse index, and the pulse index is used to evaluate the maximum deviation degree of the single kinetic parameter; The number of blade tip timing sensors; is the first determination threshold; is the second determination threshold; represents the update parameters of the twin reduced-order model; Represents the update parameters with The corresponding kinetic parameter identification results; Σ represents the sum; ‖ represents the absolute value.

8. The centrifugal impeller monitoring method based on twin reduced-order model according to claim 1, characterized in that: The step of monitoring the centrifugal impeller based on the digital model comprises: Calculating a three-dimensional response field based on the digital model; Introducing cyclic coordinates into the three-dimensional response field, and transforming the cyclic coordinates into physical coordinates to obtain a motion equation; Obtaining a modal participation factor of each independent blade based on the motion equation; The state index of the centrifugal impeller is characterized based on the modal participation factor, and the state index includes three-dimensional full-field vibration displacement and strain; when the state index is within a set range, the monitoring result of the centrifugal impeller is normal; when the state index is not within the set range, the monitoring result of the centrifugal impeller is abnormal.

9. A centrifugal impeller monitoring system based on a twin reduced-order model, wherein the centrifugal impeller is equipped with full-circumference blades, characterized in that: The monitoring system includes: A collection module collects the tip vibration signal of the full-circle blade to obtain original vibration data; A first processing module pre-processes the original vibration data to obtain blade tip vibration data; A second processing module processes the blade tip vibration data based on a keyless phase reference method to obtain a blade tip vibration displacement; A parameter identification module performs nonlinear least square curve fitting on the blade tip vibration displacement to identify the dynamic parameters of each independent blade in the full-circumference blade; A model building module, constructing a twin reduced-order model of the centrifugal impeller, and determining update parameters of the twin reduced-order model based on the dynamic parameters; A model updating module, which updates the twin reduced-order model based on the update parameters to obtain a digital model; A monitoring module, for monitoring the centrifugal impeller based on the digital model; The step of constructing the twin reduced-order model of the centrifugal impeller includes: The centrifugal impeller is divided into a first substructure and a second substructure by using a mixed interface method: The first substructure corresponds to an integrally coordinated impeller, and a model of the first substructure is generated using a coordinated mode in a harmonic nominal mode subset; The second substructure corresponds to a detuned blade, and a model of the second substructure introduces a mass detuned model or a stiffness detuned model; A twin reduced-order model of the centrifugal impeller is constructed based on the model of the first substructure and the model of the second substructure.

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