CN118296279A - Synchronous vibration parameter identification method, device and system - Google Patents
Synchronous vibration parameter identification method, device and system Download PDFInfo
- Publication number
- CN118296279A CN118296279A CN202410369445.0A CN202410369445A CN118296279A CN 118296279 A CN118296279 A CN 118296279A CN 202410369445 A CN202410369445 A CN 202410369445A CN 118296279 A CN118296279 A CN 118296279A
- Authority
- CN
- China
- Prior art keywords
- blade
- tip displacement
- blade tip
- expression
- physical response
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 112
- 230000001360 synchronised effect Effects 0.000 title claims abstract description 64
- 238000006073 displacement reaction Methods 0.000 claims abstract description 133
- 230000004044 response Effects 0.000 claims abstract description 79
- 238000005259 measurement Methods 0.000 claims abstract description 31
- 238000005516 engineering process Methods 0.000 claims description 17
- 238000013016 damping Methods 0.000 claims description 13
- 238000009434 installation Methods 0.000 description 14
- 238000002474 experimental method Methods 0.000 description 6
- 238000012937 correction Methods 0.000 description 5
- 238000012544 monitoring process Methods 0.000 description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000000306 component Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000007499 fusion processing Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Landscapes
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The invention relates to the technical field of rotating blade measurement, in particular to a synchronous vibration parameter identification method, device and system. The synchronous vibration parameter identification method derives the mathematical expression of the physical response of the blade tip displacement, applies the mathematical expression to the single-parameter method to correct the mathematical expression, and solves the problem that the traditional single-parameter method fits the measured value of the blade tip displacement as the physical response of the blade tip displacement, thereby causing large error of the identification result under the condition of large-amplitude blade vibration.
Description
Technical Field
The invention relates to the technical field of rotating blade measurement, in particular to a synchronous vibration parameter identification method, device and system.
Background
Impeller machinery is a key device in industry and has wide application in the fields of power generation, aviation, ships and the like. The blade is used as a core component of the impeller machine, and is subjected to huge centrifugal force and exciting force under extremely severe working conditions, so that severe vibration is easy to generate, and research shows that excessive vibration is one of main reasons for causing blade failure. Therefore, the vibration condition of the blades needs to be monitored in real time so as to ensure the normal operation of the impeller machinery.
The blade vibration measuring technology mainly comprises a contact measuring method and a non-contact measuring method, wherein the contact measuring method is mainly a resistance strain gauge method, and the non-contact measuring method comprises a blade tip timing method, a pulse modulation method, a tip phase method and the like. The resistance strain gauge method determines vibration parameters of a blade by attaching strain gauges to the blade where a large strain occurs and measuring vibration by the strain of the blade. The resistance strain gauge technique is mature, but the further development of the method is seriously hindered due to the defects of shorter service life, complex installation, fewer number of monitorable blades and the like. The non-contact measuring method overcomes the defects of the contact measuring method, and the non-contact measuring technology is mainly tip timing technology. The tip timing technology is developed by a pulse modulation method and a tip phase method, and can utilize a plurality of sensors arranged on a fixed casing to calculate and obtain the tip displacement, the frequency and the amplitude of the blade and other operation parameter information by comparing the actual arrival time and the theoretical arrival time of the tip, thereby realizing the monitoring of the operation condition of the impeller machinery. Compared with a strain foil measuring method, the blade tip timing technology has the advantages of long monitoring time, convenience in installation, capability of monitoring full-stage blades simultaneously and the like, is an important technical means for guaranteeing safe operation of the impeller machinery, and has wide application prospect.
Synchronous vibration is a vibration form commonly occurring in the blades of an impeller machine, and is expressed in that the vibration frequency of the blades is an integer multiple of the rotational speed frequency. Because the number of sensors installed is limited in actual measurement, signals extracted by the tip timing technology are often undersampled, and signals acquired by the sensors are easily affected by noise, rotation speed fluctuation and blade coupling or detuning, identification of vibration parameters is difficult, and an accurate identification algorithm is required to extract effective information of the vibration parameters. At present, the identification algorithm of synchronous vibration comprises a single-parameter method, a double-parameter method, an autoregressive method, a sine fitting method and the like.
The single-parameter method changes the vibration phase of the blade at the sampling moment through variable speed frequency sweep, when the rotating speed passes through the resonance point, the amplitude of the blade reaches the maximum value, and then the curve of the blade tip displacement relative to the rotating speed is obtained, and the identification of the vibration parameters of the blade can be realized by utilizing the curve. The double-parameter method needs to utilize two blade tip timing sensors, and the two blade tip timing sensors are arranged on a casing according to a certain included angle to acquire blade vibration information, and the phase difference of the two sensors during resonance is obtained by fusion processing of signals acquired by the two sensors, so that the vibration parameters of the blade are calculated. The autoregressive method needs to utilize 4 or more blade tip timing sensors distributed with equal included angles to collect blade tip vibration signals, establishes an AR model for the vibration signals collected by the sensors, and utilizes a least square method to solve the AR model to obtain vibration parameters of the blade. The sine fitting method needs to use 4 or more blade tip timing sensors for collecting blade vibration signals, establishes a vibration displacement equation based on the blade vibration signals, and finally obtains vibration parameters of the blade by using a least square method. Unlike autoregressive methods, sinusoidal fitting methods do not require constant angle mounting of tip timing sensors.
The identification methods such as a double-parameter method, a sine fitting method, an autoregressive method and the like are more in number of sensors, certain requirements are placed on the installation positions of the sensors, the data processing is complex, and certain difficulties exist in practical application; therefore, among various identification algorithms, the single-parameter method is widely used for vibration parameter identification of synchronous vibration due to advantages of low requirements on the number and position of sensors to be mounted, simple data processing, and the like, compared with other several identification algorithms. However, the single-parameter method ignores the influence of the vibration of the blade on the blade tip arrival time, the measured value of the blade tip displacement is used as the physical response of the blade tip displacement to be fitted, and the installation angle position of the sensor is directly used for identifying the vibration parameters, so that errors occur in the identification result, and particularly, larger errors occur in the identification of the vibration parameters of the blade with larger amplitude; in addition, the single-parameter method does not distinguish between the measured value of the blade tip displacement and the physical response, and the measured value of the blade tip displacement is equivalent to the physical response, so that the accurate identification of the vibration parameters is difficult to realize under the conditions of multi-modal response, steady-state displacement and blade anti-torsion angle. Because the single-parameter method has poor parameter identification results of larger-amplitude vibration on the blade, the method has great influence on the safe operation of the impeller machinery.
Therefore, the single-parameter method is corrected, so that the vibration parameters can still be accurately identified under the condition of large-amplitude synchronous vibration, and the method has important significance for guaranteeing the safe operation of the impeller machinery.
Disclosure of Invention
Therefore, the invention aims to solve the technical problem that the parameter identification result error of the single-parameter method for generating larger amplitude vibration on the blade is large in the prior art.
In order to solve the technical problems, the invention provides a synchronous vibration parameter identification method, which comprises the following steps:
measuring the blade tip displacement by utilizing a BTT technology, and obtaining a blade tip displacement measurement expression at a constant rotating speed;
Assuming that the blade is a single-mode single-degree-of-freedom vibration system with constant damping and exciting force amplitude, obtaining a steady-state solution of a blade vibration equation;
according to the steady-state solution, obtaining a blade tip displacement physical response expression under the condition that exciting force with single frequency multiplication as a main factor corresponds to the exciting force;
Under the synchronous vibration condition, substituting the blade tip displacement measurement expression under the constant rotating speed into the blade tip displacement physical response expression, and simplifying the expression to obtain a target blade tip displacement physical response expression;
and acquiring timing data of the variable rotation speed blade tip, and identifying vibration parameters of the single-parameter method corrected according to the target blade tip displacement physical response expression.
Preferably, the measuring the tip displacement by using the BTT technology, and obtaining the tip displacement measurement expression at the constant rotation speed includes:
Measuring the blade tip displacement by utilizing a BTT technology, and obtaining a blade tip displacement measurement expression;
Acquiring a rotor angular position expression at a constant rotating speed;
And obtaining the blade tip displacement measurement expression under the constant rotating speed according to the blade tip displacement measurement expression and the rotor angular position expression.
Preferably, the obtaining the physical response expression of the blade tip displacement under the condition that the exciting force with single frequency multiplication as the main part corresponds to the stable state solution includes:
assuming that the exciting force is mainly single frequency multiplication, obtaining an exciting force frequency expression;
And obtaining the blade tip displacement physical response expression according to the exciting force frequency expression and the steady-state solution.
Preferably, the target tip displacement physical response expression is:
wherein, y nij is the physical response of the blade tip displacement corresponding to the t nij time, A is the response amplitude, EO is the frequency multiplication, omega is the rotating speed, Is the designed angular position of the ith blade in the rotor coordinate system when the ith blade is not deformed,For the installation angle position of the jth blade tip timing sensor in the machine case coordinate system, x nij is the blade tip displacement measured value corresponding to the t nij moment, r is the blade tip radius,For the initial phase position,In response to the phase.
Preferably, when the blade is a straight blade, the physical response is only a single mode vibration, and the steady-state displacement of the blade during rotation is ignored, the physical response value of the tip displacement corresponding to the time t nij is equal to the measured value of the tip displacement corresponding to the time t nij.
Preferably, the obtaining variable rotation speed tip timing data and the identifying vibration parameters of the single-parameter method corrected according to the target tip displacement physical response expression includes:
Acquiring timing data of a variable rotation speed blade tip;
Calculating a tip displacement measured value according to the variable rotation speed tip timing data;
Fitting the blade tip displacement measured values by using a spline curve, and eliminating steady-state displacement to obtain a blade tip displacement physical response;
and fitting the tip displacement physical response by using the target tip displacement physical response expression through a least square method to obtain an identification result of the synchronous vibration parameter.
Preferably, the step of obtaining the identification result of the synchronous vibration parameter further includes:
And acquiring the actual running condition of the blade according to the maximum amplitude value and the natural frequency in the identification result.
The invention also provides a synchronous vibration parameter identification device, which comprises:
the blade tip displacement measurement expression acquisition module is used for measuring blade tip displacement by utilizing a BTT technology and acquiring a blade tip displacement measurement expression at a constant rotating speed;
the steady-state solution acquisition module of the vibration equation is used for acquiring a steady-state solution of the vibration equation of the blade under the assumption that the blade is a single-mode single-degree-of-freedom vibration system with damping and constant exciting force amplitude;
The physical response expression acquisition module is used for acquiring a blade tip displacement physical response expression under the condition that the exciting force with single frequency multiplication as the main component corresponds to the steady state solution;
The target physical response expression acquisition module is used for substituting the blade tip displacement measurement expression under the constant rotating speed into the blade tip displacement physical response expression under the condition of synchronous vibration, and simplifying the blade tip displacement physical response expression to obtain a target blade tip displacement physical response expression;
And the parameter identification module is used for acquiring the timing data of the variable rotation speed blade tip and carrying out the identification of the vibration parameters of the corrected single-parameter method according to the physical response expression of the target blade tip displacement.
The invention also provides a synchronous vibration parameter identification system, which comprises:
The BTT sensor is used for collecting a blade tip timing signal when the rotary blade performs variable-speed operation;
The key phase sensor is used for collecting a rotating speed signal when the rotating blade performs variable-speed operation;
the BTT data acquisition device is used for encoding the acquired signals;
The upper computer comprises the synchronous vibration parameter identification device which is used for carrying out parameter identification according to the acquired signals.
Preferably, before the parameter identification, the method further comprises:
And measuring the mounting angle of the BTT sensor, and measuring the mounting angle of the blade by using the BTT sensor and the key phase sensor under the working conditions of equal rotating speed and no deformation of the blade.
Compared with the prior art, the technical scheme of the invention has the following advantages:
the synchronous vibration parameter identification method derives the mathematical expression of the physical response of the blade tip displacement, applies the mathematical expression to the single-parameter method to correct the mathematical expression, and solves the problem that the traditional single-parameter method fits the measured value of the blade tip displacement as the physical response of the blade tip displacement, thereby causing large error of the identification result under the condition of large-amplitude blade vibration.
Drawings
In order that the invention may be more readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings, in which:
FIG. 1 is a flowchart of a synchronous vibration parameter identification method according to the present invention;
FIG. 2 is a flow chart of large amplitude synchronous vibration parameter identification by a single parameter correction method;
FIG. 3 is a flow chart of a synchronous vibration parameter identification system according to the present invention;
description of the drawings: 2-1 rotating blades; 2-2-BTT sensor; 2-3-phase sensor; 2-4-BTT data acquisition device; 2-5-upper computer.
Detailed Description
The core of the invention is to provide a method, a device and a system for identifying synchronous vibration parameters, which effectively improve the parameter identification accuracy under the vibration of a large-amplitude blade.
In order to better understand the aspects of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1, fig. 1 is a flowchart illustrating an implementation of a synchronous vibration parameter identification method according to the present invention; the specific operation steps are as follows:
S101, measuring the blade tip displacement by utilizing a BTT technology, and obtaining a blade tip displacement measurement expression at a constant rotating speed;
s102, assuming the blade is a single-mode single-degree-of-freedom vibration system with constant damping and exciting force amplitude, and obtaining a steady-state solution of a blade vibration equation;
S103, according to the steady-state solution, acquiring a blade tip displacement physical response expression under the condition that exciting force with single frequency multiplication as a main factor corresponds to the exciting force;
s104, substituting the blade tip displacement measurement expression under the constant rotating speed into the blade tip displacement physical response expression under the synchronous vibration condition, and simplifying the expression to obtain a target blade tip displacement physical response expression;
S105, acquiring timing data of the variable rotation speed blade tip, and identifying vibration parameters of the single-parameter method corrected according to the physical response expression of the target blade tip displacement.
Based on the above embodiments, the present embodiment describes step S101 in detail:
Measuring the tip displacement by using a BTT technology, and obtaining a tip displacement measurement value expression:
Wherein t nij is the time of rotation to the nth Zhou Shidi i blade to trigger the jth tip timing sensor; phi (t nij) is the angular position of the corresponding rotor at time t nij; the design angular position of the ith blade in the rotor coordinate system when the ith blade is not deformed is a known quantity; The installation angle position of the jth blade tip timing sensor in the machine case coordinate system is a known quantity; r is the tip radius; x nij is the tip displacement measurement corresponding to time t nij.
Obtaining an expression of the rotor angular position phi (t):
Wherein t key,n is the moment of triggering the key phase sensor at the beginning of the nth week, Ω is the rotational speed in rad/s.
If the rotation speed is constant, an expression of the rotor angular position phi (t nij) at the time t nij is obtained:
φ(tnij)＝Ω·tnij (3)
Order of order Substituting the formula (3) into the formula (1) to obtain a blade tip displacement measurement expression under the condition of constant rotating speed:
Then it is possible to obtain:
based on the above embodiments, the present embodiment describes step S102 in detail:
assuming that the blade is a single-mode single-degree-of-freedom vibration system with constant damping and exciting force amplitude, obtaining a vibration equation:
Wherein y is the physical response of tip displacement; delta is the damping ratio and is 2 pi times of the damping ratio; omega 0 is the natural frequency of the blade; p is the exciting force amplitude; omega is the exciting force frequency; Is the initial phase.
Obtaining a steady state solution of the above vibration equation:
In the middle of
Wherein y cm is the tip deformation under the action of static force P.
Based on the above embodiments, the present embodiment describes in detail step S103:
The frequency of the exciting force is often closely related to the rotor rotational speed, and when the rotor is operated at a constant rotational speed, it is considered that the frequency of the exciting force is not changed. Assuming that the exciting force is mainly single frequency multiplication, obtaining an expression of exciting force frequency:
ω＝EO·Ω (8)
Where EO is the frequency multiplication.
Substituting the formula (8) into the formula (7) to obtain a physical response expression of the blade tip displacement under the condition that the exciting force with single frequency multiplication is mainly corresponding to the blade tip displacement:
based on the above embodiments, the present embodiment describes in detail step S104:
Replacement of Ω·t nij with a measured value at constant rotational speed, i.e. substitution of formula (5) into formula (9) yields:
For synchronous vibration, EO is an integer, so that in the case of synchronous vibration, the reduced expression (10) can be obtained as a modified physical response expression of tip displacement calculated by a single-parameter method:
If the blade is a straight blade, the response is only a single mode vibration, and its steady state displacement during rotation is negligible, then there is:
in summary, we derive a mathematical expression of the tip displacement physical response.
The expression of the physical response of the tip displacement of the traditional single-parameter method is shown as follows:
Obviously, the single-parameter method ignores the influence of the vibration of the blade on the time item, only considers the installation position of the sensor, considers the measured value of the blade tip displacement as the physical response of the blade tip displacement, does not consider that the single-parameter method has poorer identification condition of the vibration parameter under the condition of large-amplitude synchronous vibration under the condition of larger blade tip displacement, and replaces the single-parameter method with the following method The term can eliminate errors caused by the difference between the measured value of the blade tip displacement and the physical response of the blade tip displacement; compared with the formulas (12) and (13), the high EO number can lead to the amplification of errors in cos terms of the traditional single-parameter method, so that the errors of the single-parameter method are larger under the condition of high frequency multiplication, and the mathematical expression of the tip displacement physical response provided by the invention has no problem, so that a better identification result of the maximum amplitude can be still maintained under the condition of high frequency multiplication.
Based on the above embodiments, the present embodiment describes in detail step S105:
Based on the mathematical expression of the physical response of the tip displacement, we propose a modified single-parameter vibration identification method, as shown in fig. 2:
after data acquisition is completed, calculating a blade tip displacement measured value by using the formula (1), fitting the calculated blade tip displacement measured value by using a spline curve, judging whether steady-state displacement needs to be eliminated, obtaining physical response of the blade tip displacement, and fitting by using the formula (11) through a least square method to obtain identification results of all synchronous vibration parameters. In the whole flow, input parameters comprise sensor installation angle, blade installation angle and variable rotation speed blade tip timing data, and output parameters are parameter identification results comprising maximum amplitude, frequency multiplication and damping ratio.
The single parameter correction method is compatible with synchronous vibration parameter identification under the conditions of small amplitude and large amplitude of the blade, and the parameter identification result is consistent with the single parameter method result under the condition of small amplitude, so that the method has higher precision. Under the condition of large amplitude, the single-parameter method is modified, so that the identification result of the large-amplitude synchronous vibration parameter is more accurate.
Based on the above embodiment, the present invention further includes, after obtaining the identification result of the synchronous vibration parameter:
And acquiring the actual running condition of the blade according to the maximum amplitude value, the natural frequency and other parameters in the identification result.
The embodiment of the invention also provides a synchronous vibration parameter identification device; the specific apparatus may include:
the blade tip displacement measurement expression acquisition module is used for measuring blade tip displacement by utilizing a BTT technology and acquiring a blade tip displacement measurement expression at a constant rotating speed;
the steady-state solution acquisition module of the vibration equation is used for acquiring a steady-state solution of the vibration equation of the blade under the assumption that the blade is a single-mode single-degree-of-freedom vibration system with damping and constant exciting force amplitude;
The physical response expression acquisition module is used for acquiring a blade tip displacement physical response expression under the condition that the exciting force with single frequency multiplication as the main component corresponds to the steady state solution;
The target physical response expression acquisition module is used for substituting the blade tip displacement measurement expression under the constant rotating speed into the blade tip displacement physical response expression under the condition of synchronous vibration, and simplifying the blade tip displacement physical response expression to obtain a target blade tip displacement physical response expression;
And the parameter identification module is used for acquiring the timing data of the variable rotation speed blade tip and carrying out the identification of the vibration parameters of the corrected single-parameter method according to the physical response expression of the target blade tip displacement.
The synchronous vibration parameter identification device of the present embodiment is used for implementing the synchronous vibration parameter identification method, so that the specific implementation of the synchronous vibration parameter identification device may be the example portion of the synchronous vibration parameter identification method, for example, the tip displacement measurement expression acquisition module, the vibration equation steady state solution acquisition module, the physical response expression acquisition module, the target physical response expression acquisition module, and the parameter identification module, which are respectively used for implementing steps S101, S102, S103, S104, and S105 in the synchronous vibration parameter identification method, so that the specific implementation thereof may refer to the description of the corresponding examples of each portion and will not be repeated herein.
As shown in fig. 3, the present invention further provides a synchronous vibration parameter identification system, including:
The BTT sensor is used for collecting a blade tip timing signal when the rotary blade performs variable-speed operation;
The key phase sensor is used for collecting a rotating speed signal when the rotating blade performs variable-speed operation;
the BTT data acquisition device is used for encoding the acquired signals;
the upper computer comprises the synchronous vibration parameter identification device according to claim 8, and the synchronous vibration parameter identification device is used for carrying out parameter identification according to the acquired signals.
The operation mode of the system is as follows: the tip timing signals collected by the BTT sensor and the rotating speed signals collected by the key phase sensor are transmitted to the BTT data collecting device through wires and are encoded, and then transmitted to an upper computer through a network for parameter identification.
In summary, the invention firstly needs to measure the installation angle of the BTT sensor, and measures the installation angle of the blade by using the BTT sensor and the key phase sensor under the working condition of equal rotation speed and no deformation of the blade. When the parameter identification is carried out, the rotating blade is required to carry out variable rotation speed operation, and the key phase sensor and the BTT sensor are utilized for data acquisition. After data acquisition is completed, calculating a blade tip displacement measured value by using the formula (1), and fitting the calculated blade tip displacement measured value by using a spline curve to eliminate steady-state displacement. And finally, performing function fitting on the physical response after eliminating the steady-state displacement by using a formula (11) (various fitting methods including a least square method, spline curves and the like can be used) to finally obtain the identification result of the synchronous vibration parameters. And judging the actual running condition of the blade according to the maximum amplitude value, the natural frequency and other parameters in the identification result.
Based on the above embodiment, the invention carries out numerical experiments on a common aluminum alloy straight blade to verify the effectiveness of the technical scheme provided by the invention:
The tip radius of the common aluminum alloy straight blade is 0.27m. Let the steady state displacement be 0 and consider it as a single degree of freedom spring-damped vibration model.
In experiment one, we used simulations, knowing that the vane produces synchronous vibration with eo=5 at 656rpm, and that the first order natural frequency of the vane is about 54.67HZ. By controlling the variable method, y cm, delta,The maximum amplitude value obtained by using the formulas (13) and (12) was compared with a given true maximum amplitude value. The numerical experiment results show that when y cm, namely the amplitude of the exciting force is increased, the maximum amplitude error identified by the traditional single-parameter method exceeds 10 percent, and the tendency of the maximum amplitude error to be greatly increased along with the increase of the exciting force is presented. The maximum amplitude error can be reduced to within 1% by adopting the single-parameter method corrected by the invention. Therefore, the method solves the problem of larger identification error of the traditional single-parameter method on the maximum amplitude parameter, and improves the identification accuracy under the condition of large amplitude.
Considering the numerical value experiment of the same experiment, when the damping ratio and the exciting force are increased, the maximum amplitude identification error of the traditional single-parameter method is greatly increased, the error is easy to exceed 15%, and the identification error result of the modified single-parameter method is always kept within 1% under the same condition. In addition, the traditional single-parameter method has the error of periodic fluctuation within 10% and-10% along with the change of the installation angle, and the cycle number is consistent with the EO number. And when the installation angle of the correction single-parameter method is changed, the error result can still be kept within 1 percent all the time. Therefore, the invention solves the problem that the error of the traditional single-parameter method for identifying the maximum amplitude can be increased along with the increase of the exciting force and the decrease of the damping ratio, solves the problem that the identification error of the traditional single-parameter method can be changed periodically along with the change of the installation angle of the sensor, and improves the identification precision.
Through experiments on a BTT laboratory table, the identification results of the modified single-parameter method and the traditional single-parameter method are almost consistent under the condition of low EO number. Therefore, the invention solves the problem that the single-parameter method can amplify the maximum amplitude identification error under the condition of high frequency multiplication exciting force frequency, and the new correction method has high accuracy for identifying the maximum amplitude under the conditions of low frequency multiplication and high frequency multiplication.
The test is carried out on a real blade on a BTT calibration table, the amplitude generated by the blade is small, and the maximum physical displacement of the blade tip is only about 4mm, so that the blade tip can be regarded as small-amplitude synchronous vibration. Fitting is carried out by a single-parameter method and a modified single-parameter method respectively, and the relative errors of the two identification results of the maximum amplitude, the damping ratio and other parameters are within 0.1 percent. Therefore, the method is used for correcting the single-parameter method with good recognition effect on the small-amplitude synchronous vibration, the recognition precision of the traditional single-parameter method under the condition of the small-amplitude synchronous vibration is reserved, and the recognition precision under the condition of the large-amplitude synchronous vibration is improved through correction, so that the method is compatible with parameter recognition on the large-amplitude synchronous vibration and the small-amplitude synchronous vibration, and has high recognition precision on both conditions.
It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations and modifications of the present invention will be apparent to those of ordinary skill in the art in light of the foregoing description. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.
Claims (10)
1. A synchronous vibration parameter identification method, comprising:
measuring the blade tip displacement by utilizing a BTT technology, and obtaining a blade tip displacement measurement expression at a constant rotating speed;
Assuming that the blade is a single-mode single-degree-of-freedom vibration system with constant damping and exciting force amplitude, obtaining a steady-state solution of a blade vibration equation;
according to the steady-state solution, obtaining a blade tip displacement physical response expression under the condition that exciting force with single frequency multiplication as a main factor corresponds to the exciting force;
Under the synchronous vibration condition, substituting the blade tip displacement measurement expression under the constant rotating speed into the blade tip displacement physical response expression, and simplifying the expression to obtain a target blade tip displacement physical response expression;
and acquiring timing data of the variable rotation speed blade tip, and identifying vibration parameters of the single-parameter method corrected according to the target blade tip displacement physical response expression.
2. The synchronous vibration parameter identification method according to claim 1, wherein the measuring the tip displacement by using BTT technology, the obtaining the tip displacement measurement expression at the constant rotation speed includes:
Measuring the blade tip displacement by utilizing a BTT technology, and obtaining a blade tip displacement measurement expression;
Acquiring a rotor angular position expression at a constant rotating speed;
And obtaining the blade tip displacement measurement expression under the constant rotating speed according to the blade tip displacement measurement expression and the rotor angular position expression.
3. The method for identifying synchronous vibration parameters according to claim 1, wherein the obtaining, according to the steady-state solution, a tip displacement physical response expression under the condition that the exciting force with single frequency multiplication as a main component corresponds to the exciting force comprises:
assuming that the exciting force is mainly single frequency multiplication, obtaining an exciting force frequency expression;
And obtaining the blade tip displacement physical response expression according to the exciting force frequency expression and the steady-state solution.
4. The synchronous vibration parameter identification method according to claim 1, wherein the target tip displacement physical response expression is:
wherein, y nij is the physical response of the blade tip displacement corresponding to the t nij time, A is the response amplitude, EO is the frequency multiplication, omega is the rotating speed, Is the designed angular position of the ith blade in the rotor coordinate system when the ith blade is not deformed,For the mounting angular position of the jth blade tip timing sensor in the case coordinate system,
X nij is the tip displacement measurement corresponding to time t nij, r is the tip radius,For the initial phase position,In response to the phase.
5. The method according to claim 4, wherein when the blade is a straight blade, the physical response is only single-mode vibration, and the steady-state displacement of the blade during rotation is ignored, the physical response value of the tip displacement corresponding to the time t nij is equal to the measured value of the tip displacement corresponding to the time t nij.
6. The synchronous vibration parameter identification method according to claim 1, wherein the obtaining variable rotation speed tip timing data and correcting the single-parameter vibration parameter identification according to the target tip displacement physical response expression comprises:
Acquiring timing data of a variable rotation speed blade tip;
Calculating a tip displacement measured value according to the variable rotation speed tip timing data;
Fitting the blade tip displacement measured values by using a spline curve, and eliminating steady-state displacement to obtain a blade tip displacement physical response;
and fitting the tip displacement physical response by using the target tip displacement physical response expression through a least square method to obtain an identification result of the synchronous vibration parameter.
7. The method for identifying synchronous vibration parameters according to claim 6, wherein the step of obtaining the identification result of the synchronous vibration parameters further comprises:
And acquiring the actual running condition of the blade according to the maximum amplitude value and the natural frequency in the identification result.
8. A synchronous vibration parameter identification device, comprising:
the blade tip displacement measurement expression acquisition module is used for measuring blade tip displacement by utilizing a BTT technology and acquiring a blade tip displacement measurement expression at a constant rotating speed;
the steady-state solution acquisition module of the vibration equation is used for acquiring a steady-state solution of the vibration equation of the blade under the assumption that the blade is a single-mode single-degree-of-freedom vibration system with damping and constant exciting force amplitude;
The physical response expression acquisition module is used for acquiring a blade tip displacement physical response expression under the condition that the exciting force with single frequency multiplication as the main component corresponds to the steady state solution;
The target physical response expression acquisition module is used for substituting the blade tip displacement measurement expression under the constant rotating speed into the blade tip displacement physical response expression under the condition of synchronous vibration, and simplifying the blade tip displacement physical response expression to obtain a target blade tip displacement physical response expression;
And the parameter identification module is used for acquiring the timing data of the variable rotation speed blade tip and carrying out the identification of the vibration parameters of the corrected single-parameter method according to the physical response expression of the target blade tip displacement.
9. A synchronous vibration parameter identification system, comprising:
The BTT sensor is used for collecting a blade tip timing signal when the rotary blade performs variable-speed operation;
The key phase sensor is used for collecting a rotating speed signal when the rotating blade performs variable-speed operation;
the BTT data acquisition device is used for encoding the acquired signals;
the upper computer comprises the synchronous vibration parameter identification device according to claim 8, and the synchronous vibration parameter identification device is used for carrying out parameter identification according to the acquired signals.
10. The synchronous vibration parameter identification system according to claim 9, wherein the pre-parameter identification further comprises:
And measuring the mounting angle of the BTT sensor, and measuring the mounting angle of the blade by using the BTT sensor and the key phase sensor under the working conditions of equal rotating speed and no deformation of the blade.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410369445.0A CN118296279A (en) | 2024-03-28 | 2024-03-28 | Synchronous vibration parameter identification method, device and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410369445.0A CN118296279A (en) | 2024-03-28 | 2024-03-28 | Synchronous vibration parameter identification method, device and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118296279A true CN118296279A (en) | 2024-07-05 |
Family
ID=91688748
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410369445.0A Pending CN118296279A (en) | 2024-03-28 | 2024-03-28 | Synchronous vibration parameter identification method, device and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118296279A (en) |
-
2024
- 2024-03-28 CN CN202410369445.0A patent/CN118296279A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111579060B (en) | High-precision rotating blade vibration measurement method based on blade tip timing technology | |
| US4955269A (en) | Turbine blade fatigue monitor | |
| Heath et al. | A survey of blade tip-timing measurement techniques for turbomachinery vibration | |
| CN109974849B (en) | Blade vibration online monitoring method based on blade tip timing technology under condition of no reference signal | |
| CN101625260B (en) | Method for detecting high speed rotating blade synchronous vibration parameters under speed change | |
| CN108731896B (en) | Vibration monitoring device for movable blade of gas turbine compressor | |
| EP0327865B1 (en) | Turbine blade fatigue monitor | |
| CN109540482B (en) | Method and device for analyzing keyless synchronous vibration parameters of turbine blade | |
| CN109813423B (en) | Method and device for monitoring vibration displacement of turbine mechanical blade | |
| CN110851963A (en) | Casing circumferential arrangement method of blade end timing sensor | |
| CN110686764A (en) | Method for measuring asynchronous vibration frequency of constant-speed blade based on full-phase difference principle | |
| US20120312099A1 (en) | Rotating blade analysis | |
| CN102967414B (en) | Method for extracting imbalanced components of micro-speed-difference double-rotor system based on frequency spectrum correction | |
| CN110319922A (en) | Blade twist vibration displacement measurement method based on Tip-Timing principle | |
| CN103868649A (en) | On-line dynamic balancing correction method for rotors of double-rotor axial flow fan | |
| CN102288362A (en) | System and method for testing unsteady surface pressure of vibrating blade | |
| CN115435894B (en) | Blade tip timing vibration stress inversion method based on simulated annealing algorithm | |
| Fan et al. | Shifting straight-line fitting method to calculate blade vibration based on blade tip timing | |
| Heath et al. | A review of analysis techniques for blade tip-timing measurements | |
| CN116577050A (en) | Method for testing dynamic damping ratio of aero-engine compressor rotor blade | |
| CN112733600A (en) | Blade fault diagnosis method without rotating speed reference signal | |
| Ren et al. | An error correction blade tip-timing method to improve the measured accuracy of blade vibration displacement during unstable rotation speed | |
| Fan et al. | An improved multiple per revolution-based blade tip timing method and its applications on large-scale compressor blades | |
| CN110646138B (en) | Rotary machine keyless phase non-test weight dynamic balance method and analysis device | |
| CN113495169B (en) | Wind speed ultrasonic measurement system in front of wind wheel of wind turbine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |