A vibration test system and method for engine blades

Abstract

The invention discloses a vibration test system and method for engine blades, which relate to the technical field of engine blade detection, and include a data acquisition module, a first abnormal monitoring module, a second abnormal monitoring module and an abnormal judgment module; the blades are specifically marked, and monitoring points are set on the casing; the first monitoring point device is started when the rotation speed is stable, the vibration displacement of the blades is recorded, and the average amplitude of each blade is calculated and integrated to determine whether to trigger an abnormal monitoring instruction; when the abnormal monitoring instruction is triggered, the second monitoring point device is started, the vibration and sound signals of the blades are analyzed in the frequency domain, abnormal and normal frequency spectrum diagrams are established, and the comprehensive difference of vibration and sound is calculated; the comprehensive abnormal judgment index of each blade is calculated by combining the two comprehensive differences, the vibration abnormality is determined, and whether to stop the generator is determined according to the number of abnormal blades; a buffer blade mechanism is introduced, and the abnormality is further verified by using multi-cycle data; and comprehensive and accurate monitoring of the vibration of the engine blades is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of engine blade detection, and in particular to a vibration test system and method for engine blades. Background Art

[0002] The vibration test of engine blades is an important technical means to ensure the safe and efficient operation of the engine. As the core components of various large rotating machinery, such as aircraft engines, gas turbines, steam turbines, flue gas turbines, blowers, etc., the working efficiency and safe operation of blades are directly related to the performance and service life of the entire equipment. Blades are subjected to huge loads during operation, including the combined effects of centrifugal force, fluid dynamics, vibration, thermal stress, etc., and are prone to vibration, which can lead to blade fatigue and even cracks, breakage and other failures. According to statistics, most blade damage failures are caused by vibration, so the study of blade vibration characteristics is particularly important.

[0003] During the operation of the blades, due to the presence of air flow or gas flow, the blades are subjected to the airflow force that changes with time. The alternating force and torque generated by the transmission parts or rotating parts will also cause the blades to be subjected to mechanical forces. In addition, the blades may also be subjected to a variety of complex forces, such as flutter and self-excited vibration caused by rotating stall. If these vibrations continue to occur in a long-term operating state, the safe service life of the blades will be shortened, and even serious accidents will be caused. Therefore, the blade vibration measurement technology during the operation of the blades came into being.

[0004] Existing vibration test systems for engine blades often only set up a small number of fixed monitoring points at certain key positions of the engine, which may make it impossible to comprehensively and intelligently capture the vibration conditions of the blades. In addition, existing vibration test systems for engine blades often rely on a single sensor type (such as traditional blade tip timing sensors) to collect vibration data, but lack fusion analysis of multi-source data, such as the combination of vibration data and sound data, resulting in inaccurate detection results. Finally, existing vibration test systems for engine blades often test multiple blades as a whole, but do not perform abnormality detection on each blade, which may result in the inability to promptly discover problems with a blade, that is, the inability to promptly locate the blade with abnormal vibration. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In response to the technical problems in the background technology, the present invention proposes a vibration testing system and method for engine blades, wherein multiple integrated sensor devices are evenly placed on the engine casing, and different numbers of sensors are triggered to operate under different circumstances; the frequency domain analysis results of the vibration signal and the sound signal are combined to identify the amplitude of the abnormal frequency and calculate the comprehensive abnormality judgment index of each blade, and whether the blade has vibration abnormality is determined by combining the number of abnormal blades and the monitoring cycle interval; thereby solving the technical problems recorded in the background technology.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A vibration test system for an engine blade, comprising:

[0010] The data acquisition module performs RFID tagging for each blade on the engine impeller; a first monitoring point and a second monitoring point are respectively set on the engine casing, and vibration displacement data and sound signals are acquired at each monitoring point; when the engine is in normal operation, the monitoring of vibration displacement data at the first monitoring point is started;

[0011] The first abnormal monitoring module records the vibration displacement data of each blade monitored in the time series diagram of the corresponding blade; calculates the average amplitude of the blade in a monitoring cycle based on the number of first monitoring points, and combines the average amplitude of all blades to obtain the comprehensive average amplitude of the engine blade in each monitoring cycle. , and determine whether to trigger an abnormal monitoring instruction;

[0012] The second abnormal monitoring module, when the abnormal monitoring instruction is triggered, starts the monitoring of the vibration displacement data and sound signals at the first and second monitoring points; performs frequency domain analysis on the vibration signals and sound signals of each blade monitored, and establishes a comprehensive vibration spectrum diagram and a comprehensive sound spectrum diagram respectively; establishes a vibration abnormal multiple frequency set and a sound abnormal multiple frequency set based on the magnitude relationship of the amplitude under the corresponding multiple frequency, and calculates the vibration comprehensive difference respectively And the overall difference of sound ;

[0013] The abnormal judgment module combines the comprehensive difference of vibration of each blade in each monitoring cycle And the overall difference of sound , get the comprehensive abnormality judgment index of each leaf , and determine whether each blade has abnormal vibration; decide whether to trigger the generator stop command based on the number of blades with abnormal vibration; set up a buffer blade mechanism, and combine multiple monitoring cycles to further determine whether abnormal vibration occurs.

[0014] Specifically, each integrated sensor device is placed at 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315° on the upper edge of the casing of the impeller; the integrated sensor devices at 0°, 90°, 180° and 270° on the upper edge of the casing of the impeller are recorded as the first monitoring point, and the integrated sensor devices at 45°, 135°, 225° and 315° on the upper edge of the casing of the impeller are recorded as the second monitoring point.

[0015] Specifically, when a blade enters the monitoring area of ​​the integrated sensor device, the RFID tag of the blade is identified, and the vibration displacement data of the blade is monitored; the monitored real-time vibration displacement data is recorded in a time series diagram of the corresponding blade; within a monitoring cycle, four consecutive vibration displacement-time change diagrams will appear in the time series diagram of each blade; the average amplitude of each vibration displacement-time change diagram is calculated respectively, and then the four average amplitudes calculated based on the four vibration displacement-time change diagrams of each blade are combined to obtain the average amplitude of each blade in each monitoring cycle.

[0016] Furthermore, the average amplitudes of all blades in each monitoring cycle are combined to obtain the comprehensive average amplitude of the engine blades in each monitoring cycle. , the expression is:

[0017] ;

[0018] in, Indicates the total number of blades in the engine. Indicates the engine leaves, Indicates Passing through the integrated sensor device, Indicates the number of The leaves in The time it takes to enter the monitoring range of the integrated sensor device. Indicates the number of The leaves in The time when the device leaves the monitoring range of the integrated sensor device; Indicates the absolute value of the vibration displacement and time in each vibration displacement-time change diagram The corresponding relationship;

[0019] The comprehensive average amplitude of each monitoring cycle The integrated average amplitude threshold Compared with the above, the comprehensive average amplitude threshold is the preset blade amplitude threshold. times, and ;

[0020] like, The exception monitoring instruction is not triggered; if , then the abnormal monitoring instruction is triggered.

[0021] Specifically, the real-time vibration displacement data and sound signal of each blade are obtained; the monitored vibration displacement data are arranged in time series to construct the vibration signal of the blade;

[0022] Perform Fourier transform on the vibration signal and sound signal of each blade, convert the time domain signal into frequency domain signal, and obtain the vibration spectrum and sound spectrum in 8 time periods respectively;

[0023] For any blade, the vibration shift spectrum and sound spectrum in the eight time periods are averaged at the corresponding frequencies, and the calculated amplitude result is assigned to the corresponding frequency; based on the new amplitude after the average calculation at each frequency, the comprehensive vibration spectrum and comprehensive sound spectrum in each monitoring period are established;

[0024] Obtain the vibration displacement data and sound signals corresponding to several time periods monitored during normal operation without any abnormality in the historical data, convert the time domain signals into frequency domain signals, and perform the mean operation of the amplitude at the same frequency in several time periods to obtain the normal vibration spectrum diagram and normal sound spectrum diagram.

[0025] Further, starting from the lowest multiple frequency of the comprehensive vibration spectrum and the comprehensive sound spectrum, the vibration amplitude corresponding to each multiple frequency of the comprehensive vibration spectrum and the comprehensive sound spectrum is obtained in sequence. and sound amplitude , as well as the normal vibration spectrum and the standard vibration amplitude corresponding to each frequency in the normal sound spectrum and standard sound amplitude ;

[0026] like , it means that the vibration amplitude under the corresponding frequency multiple exceeds the standard vibration amplitude, and the frequency multiple is placed in the vibration abnormal frequency multiple set; if , it means that the sound amplitude at the corresponding frequency exceeds the standard sound amplitude, and the frequency is placed in the abnormal sound frequency set.

[0027] Furthermore, based on the data of each frequency multiple in the vibration abnormal frequency multiple set and the sound abnormal frequency multiple set, the Euclidean distance between the vibration amplitude at all frequencies and the standard vibration amplitude, and the Euclidean distance between the sound amplitude at all frequencies and the standard sound amplitude are calculated, which are recorded as the vibration comprehensive difference And the overall difference of sound , the expression is:

[0028] ;

[0029] in, , Respectively represent the total number of data in the vibration abnormal multiple frequency set and the sound abnormal multiple frequency set, , They represent the abnormal vibration frequency concentration The vibration amplitude corresponding to each frequency multiple and the standard vibration amplitude; , They represent the abnormal frequency concentration of the sound. The sound amplitude corresponding to each octave and the standard sound amplitude.

[0030] Furthermore, the vibration comprehensive difference calculated in each monitoring cycle is And the overall difference of sound Combined, the comprehensive abnormality judgment index of each leaf is obtained , the expression is:

[0031] ;

[0032] in, , They represent the weight ratio coefficients of vibration data and sound data respectively. The specific values ​​are set by the generator management personnel. , ; , They represent the vibration comprehensive difference threshold and the sound comprehensive difference threshold respectively; Indicates when When , the value in the brackets is 1; when When , the value in the brackets is .

[0033] Furthermore, if , then it means If a blade vibrates abnormally, , then it means No abnormal vibration occurred in the blades;

[0034] Count the number of blades with abnormal vibration in each monitoring cycle ,like , then the generator stop command is triggered;

[0035] like , then further judgment is made in combination with the abnormal judgment result of the next monitoring cycle, the RFID tags of the blades with abnormal vibration in the current monitoring cycle are recorded and these blades are recorded as buffer blades;

[0036] If the number of blades with abnormal vibration in the next monitoring period is greater than or equal to , the generator stop command is triggered; if the number of blades with abnormal vibration in the next monitoring cycle is less than , it is determined whether there is a blade corresponding to the buffer blade recorded in the previous monitoring cycle among the abnormal blades. If yes, an abnormal vibration alarm of the corresponding blade is sent to the generator manager; if no, the buffer blade recorded in the previous monitoring cycle is cleared, and the abnormal vibration blade detected in the next monitoring cycle is marked as a buffer blade;

[0037] If no blade with abnormal vibration is detected in two consecutive monitoring cycles, the monitoring callback instruction is triggered.

[0038] A vibration test method for an engine blade, comprising:

[0039] Step 1: RFID tag each blade on the engine impeller; set a first monitoring point and a second monitoring point on the engine casing, respectively, and obtain vibration displacement data and sound signals at each monitoring point; when the engine is in normal operation, start monitoring the vibration displacement data at the first monitoring point;

[0040] Step 2: Record the vibration displacement data of each blade monitored in the time series diagram of the corresponding blade; calculate the average amplitude of the blade in a monitoring cycle based on the number of the first monitoring points, and combine the average amplitude of all blades to obtain the comprehensive average amplitude of the engine blade in each monitoring cycle. , and determine whether to trigger an abnormal monitoring instruction;

[0041] Step 3: When the abnormal monitoring instruction is triggered, the monitoring of the vibration displacement data and the sound signal at the first and second monitoring points is started; the vibration signals and sound signals of each blade monitored are analyzed in the frequency domain, and a comprehensive vibration spectrum diagram and a comprehensive sound spectrum diagram are established respectively; based on the magnitude relationship of the amplitude under the corresponding multiple frequency, a vibration abnormal multiple frequency set and a sound abnormal multiple frequency set are established respectively, and the vibration comprehensive difference is calculated respectively And the overall difference of sound ;

[0042] Step 4: Combine the comprehensive vibration difference of each blade in each monitoring cycle And the overall difference of sound , get the comprehensive abnormality judgment index of each leaf , and determine whether each blade has abnormal vibration; decide whether to trigger the generator stop command based on the number of blades with abnormal vibration; set up a buffer blade mechanism, and combine multiple monitoring cycles to further determine whether abnormal vibration occurs.

[0043] (III) Beneficial effects

[0044] The present invention provides a vibration test system and method for engine blades, which have the following beneficial effects:

[0045] 1. By marking each blade with RFID and combining it with a fiber-optic blade tip timing sensor and an acoustic sensor, accurate monitoring of the vibration and acoustic signals of each blade is achieved; at the same time, the reasonable sensor layout not only improves the accuracy and reliability of the vibration test, but also provides a solid foundation for subsequent fault diagnosis and performance evaluation;

[0046] 2. By acquiring and recording the vibration displacement data of each blade in real time, calculating the average amplitude of the blade within a monitoring cycle, and combining the comprehensive average amplitude of all blades to determine whether to trigger an abnormal monitoring instruction; this can accurately monitor the vibration state of the engine blades and detect abnormal vibration in time, providing effective technical support for the safe operation and fault prevention of the engine, while improving the accuracy and reliability of vibration testing;

[0047] 3. By triggering the abnormal monitoring command and opening the second monitoring point, the vibration and sound signals of the blades are analyzed in the frequency domain, and the spectrum diagrams of abnormal and normal are compared to effectively identify the abnormal frequency multiplication set; combined with the comprehensive difference evaluation of vibration and sound, the system can more accurately judge the vibration abnormality of the engine blades, improve the accuracy of fault detection, and provide strong guarantee for the safe operation of the engine;

[0048] 4. By comprehensively considering the comprehensive difference between vibration and sound, a comprehensive abnormality judgment index for blades was established, realizing accurate identification of blade vibration abnormalities. The introduction of a buffer blade mechanism combined with data from multiple monitoring cycles for further judgment effectively reduced the false alarm rate and improved the reliability and stability of the system. This not only enables timely detection and processing of blade vibration abnormalities, but also automatically triggers corresponding processing instructions based on abnormal conditions, providing a strong guarantee for the safe operation of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic structural diagram of a vibration test system for engine blades provided by the present invention;

[0050] Figure 2 A flow chart of the steps of a vibration testing method for engine blades provided by the present invention. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] refer to Figure 1 The present invention provides a vibration test system for engine blades, comprising:

[0053] The data acquisition module performs RFID tagging for each blade on the engine impeller; a first monitoring point and a second monitoring point are respectively set on the engine casing, and vibration displacement data and sound signals are acquired at each monitoring point; when the engine is in normal operation, the monitoring of vibration displacement data at the first monitoring point is started;

[0054] The data acquisition module includes the following steps:

[0055] Step 101, based on the blade tip timing method, the vibration data of each blade in the engine impeller is monitored. The blade tip timing method is to install the blade tip timing sensor on the rotor casing along the circumference of the impeller, and install a speed sensor near the rotating shaft; when the impeller starts to rotate, the blade tip timing sensor detects that a blade passes through, that is, enters the monitoring area, it will generate a blade pulse signal, the speed sensor senses the sensing material attached to the rotating shaft and generates a speed pulse signal, and records the time interval between the rising edge of each speed pulse and the rising edge of all blade pulses; during the rotation of the blade disk, when the blade undergoes tangential bending vibration, the blade will vibrate and deform, and the blade end will produce a forward or backward vibration displacement, resulting in the blade end reaching the blade tip timing sensor. The time is advanced or delayed relative to when the blade does not vibrate; by measuring the time difference and according to the geometric position relationship of the blade on the impeller, the vibration data of the blade, that is, the vibration displacement, can be calculated;

[0056] The blade tip timing sensor is an optical fiber blade tip timing sensor, which transmits laser to the blade end through the transmitting end, and senses the arrival time of the blade by comparing the light intensity signal reflected from the blade end with the change in the transmitted light intensity signal;

[0057] Step 102: Using a sound sensor to monitor the sound signal of each blade when the generator is running, and analyzing whether the blade has abnormal vibration in combination with the vibration of the blade and the sound transmitted can make the judgment result more accurate;

[0058] Step 103, embedding an RFID tag in the area near the tip of each blade on the engine impeller;

[0059] Select an RFID reader / writer, design the above-selected optical fiber blade tip timing sensor, sound sensor and RFID reader / writer into independent modules respectively, and integrate them into the same device based on the interface and protocol of each module to realize monitoring of the vibration data and sound data of the specified blade; this device is recorded as an integrated sensor device;

[0060] Each integrated sensor device is installed on the generator casing and distributed along the circumference of the impeller to ensure that the passage of each blade can be detected; a total of 8 integrated sensor devices are placed, and each integrated sensor device is placed on the casing at 0° (360°), 45°, 90°, 135°, 180°, 225°, 270° and 315° along the impeller in sequence; the integrated sensor devices at 0°, 90°, 180° and 270° on the casing are recorded as the first monitoring point, and the integrated sensor devices at 45°, 135°, 225° and 315° on the casing are recorded as the second monitoring point;

[0061] When the blade rotates past the integrated sensor device, the RFID reader in the integrated sensor device reads the coded mark and generates a corresponding signal, which includes the identification code of the RFID tag; the collected signal is decoded and matched with the preset blade coding database to identify the corresponding blade;

[0062] Step 104, placing an electromagnetic pulse sensor on the crankshaft of the engine to monitor the rotational speed of the engine blades; when the engine speed is stable, turning on the integrated sensor device at the first monitoring point on the casing to monitor the vibration data of each blade, wherein the stable speed means that the speed reaches the speed value required for the engine operation and the speed does not change within a preset time.

[0063] When using, combine the contents in steps 101 to 104:

[0064] By tagging each blade with RFID and combining it with a fiber-optic blade tip timing sensor and an acoustic sensor, accurate monitoring of the vibration and acoustic signals of each blade is achieved. At the same time, a reasonable sensor layout not only improves the accuracy and reliability of vibration testing, but also provides a solid foundation for subsequent fault diagnosis and performance evaluation.

[0065] The first abnormal monitoring module records the vibration displacement data of each blade monitored in the time series diagram of the corresponding blade; calculates the average amplitude of the blade in a monitoring cycle based on the number of first monitoring points, and combines the average amplitude of all blades to obtain the comprehensive average amplitude of the engine blade in each monitoring cycle. , and determine whether to trigger an abnormal monitoring instruction;

[0066] The first abnormality monitoring module includes the following steps:

[0067] Step 201, setting a monitoring cycle, the length of which is the length of one rotation cycle of the blade, wherein the length of one rotation cycle of the blade is the time required for each blade to rotate once, that is, to rotate 360°, which is specifically calculated by the rotation speed of the engine blade; collecting vibration data in the integrated sensor device in each monitoring cycle;

[0068] Step 202: When each integrated sensor device detects that a blade enters the monitoring area, the RFID tag of the blade is identified, and the vibration displacement data of the blade is monitored. During the monitoring of the vibration data of each blade, the monitored real-time vibration displacement data is recorded in a time series diagram of the corresponding blade.

[0069] Step 203, within a monitoring cycle, each blade will sequentially pass through four integrated sensor devices placed at the first monitoring point on the casing, that is, four consecutive vibration displacement-time change graphs will appear in the time series graph of each blade, corresponding to the vibration displacement change data monitored when passing through each integrated sensor device;

[0070] According to each section of the vibration displacement-time variation diagram of each blade, the average amplitude of each section of the vibration displacement-time variation diagram is calculated respectively, and then the four average amplitudes calculated according to the four sections of the vibration displacement-time variation diagram of each blade are combined to obtain the average amplitude of each blade in each monitoring cycle; then the average amplitudes of all blades in each monitoring cycle are combined to obtain the comprehensive average amplitude of the engine blade in each monitoring cycle , the expression is:

[0071] ;

[0072] in, Indicates the total number of blades in the engine. Indicates the engine leaves, Indicates Passing through the integrated sensor device, Indicates the number of The leaves in The time it takes to enter the monitoring range of the integrated sensor device. Indicates the number of The leaves in The time when the device leaves the monitoring range of the integrated sensor device; Indicates the absolute value of the vibration displacement and time in each vibration displacement-time change diagram The corresponding relationship is specifically based on the trapezoidal integration method to calculate the total vibration displacement in each period of time. The trapezoidal integration method for calculating the area of ​​a region is a numerical integration method. It divides the area to be calculated into a series of trapezoids and calculates the sum of the areas of these trapezoids to approximate the area of ​​the original region.

[0073] Step 204: Obtain blade amplitude threshold The blade amplitude threshold represents the vibration data of the engine blade when it is in normal operation, which is obtained based on the vibration data monitored during the normal operation of the historical blade; the calculated comprehensive average amplitude of each monitoring cycle The preset comprehensive average amplitude threshold Compared with the above, the comprehensive average amplitude threshold is the blade amplitude threshold of times, The value of is set by the engine equipment manager, and ;

[0074] like, , it means that there is no abnormal vibration of the engine blades in the current monitoring cycle, and the abnormal monitoring instruction is not triggered; if , it means that abnormal vibration of the engine blades may occur during the current monitoring period, triggering the abnormal monitoring instruction.

[0075] When using, combine the contents in steps 201 to 204:

[0076] By acquiring and recording the vibration displacement data of each blade in real time, calculating the average amplitude of the blade within a monitoring cycle, and combining the comprehensive average amplitude of all blades to determine whether to trigger an abnormal monitoring instruction; this can accurately monitor the vibration state of the engine blades and detect abnormal vibration conditions in a timely manner, providing effective technical support for the safe operation and fault prevention of the engine, while improving the accuracy and reliability of vibration testing.

[0077] The second abnormal monitoring module, when the abnormal monitoring instruction is triggered, starts the monitoring of the vibration displacement data and sound signals at the first and second monitoring points; performs frequency domain analysis on the vibration signals and sound signals of each blade monitored, and establishes a comprehensive vibration spectrum diagram and a comprehensive sound spectrum diagram respectively; establishes a vibration abnormal multiple frequency set and a sound abnormal multiple frequency set based on the magnitude relationship of the amplitude under the corresponding multiple frequency, and calculates the vibration comprehensive difference respectively And the overall difference of sound ;

[0078] The second abnormality monitoring module includes the following steps:

[0079] Step 301, after the abnormal monitoring instruction in step 204 is triggered, the number of monitoring times of the blades in one monitoring cycle is adjusted and the frequency domain analysis of the blade vibration data and sound data is performed; wherein, the number of monitoring times of the blades in one monitoring cycle is adjusted specifically by turning on the integrated sensor device at the second monitoring point position on the casing to monitor the vibration data and sound data of each blade, that is, each blade is monitored a total of 8 times in one monitoring cycle;

[0080] Perform frequency domain analysis of blade vibration data and sound data by performing frequency domain analysis on multiple vibration signals and sound signals monitored within a monitoring cycle, and perform abnormal vibration detection within each monitoring cycle based on the established spectrum diagram;

[0081] Step 302: Arrange the monitored vibration displacement data in time series to construct a vibration signal of the blade; collect the sound signal of each blade passing by based on the sound sensor in the integrated sensor device;

[0082] The collected vibration signal and sound signal are preprocessed respectively, wherein the vibration signal is denoised, trend-removed and normalized; the vibration signal is often mixed with noise signals, which may come from the environment, the sensor itself or the transmission process. Digital filtering techniques such as low-pass filtering and band-pass filtering are used to remove these noises; there may be trend terms in the vibration signal, that is, the overall trend of the signal changing over time. The trend term will affect the spectral characteristics of the signal, resulting in inaccurate results of frequency domain analysis. Polynomial least squares are used to eliminate the influence of the trend term; in order to facilitate subsequent processing and analysis and reduce analysis errors caused by amplitude differences, the vibration signal is normalized;

[0083] De-noising and pre-emphasis processing are performed on the sound signal; Noise is a common interference factor in sound signals. In order to remove or weaken the noise component, noise suppression techniques such as spectral subtraction and Wiener filtering are used to separate the signal and noise in the frequency domain or time domain, thereby retaining the useful speech components; The high-frequency part of the sound signal is often more susceptible to noise interference and attenuation than the low-frequency part. In order to compensate for the loss of the high-frequency part and improve the high-frequency resolution of the signal, pre-emphasis technology is used, which is specifically achieved through a first-order FIR high-pass digital filter, which increases the amplitude of the high-frequency part without changing the low-frequency component of the signal;

[0084] Step 303: At the end of each monitoring cycle, Fourier transform is performed on the vibration signal and the sound signal of each blade, and the time domain signal is converted into a frequency domain signal, and a vibration spectrum diagram and a sound spectrum diagram in 8 time periods are obtained, respectively. The 8 time periods represent the duration of each entry and exit from the monitoring range of the integrated sensor device;

[0085] For any blade, the vibration shift spectrum and sound spectrum in the eight time periods are averaged at the corresponding frequencies, that is, the amplitudes at the same frequency in the eight time periods are averaged, and the calculated amplitude results are assigned to the corresponding frequencies; based on the new amplitudes after the average calculation at each frequency, a comprehensive vibration spectrum and a comprehensive sound spectrum are established in each monitoring period;

[0086] Step 304: Obtain the vibration displacement data and sound signals corresponding to several time periods monitored when there is no abnormality and normal operation in the historical data, convert the time domain signal into a frequency domain signal according to the same method as above according to the duration of each entry and exit from the monitoring range of the integrated sensor device, and perform an average operation of the amplitude at the same frequency in several time periods to obtain a normal vibration spectrum diagram and a normal sound spectrum diagram;

[0087] Step 305: Starting from the lowest multiple frequency (base frequency is 50 Hz) of the comprehensive vibration spectrum and the comprehensive sound spectrum, the vibration amplitude corresponding to each multiple frequency in the comprehensive vibration spectrum and the comprehensive sound spectrum is obtained in sequence. and sound amplitude , as well as the normal vibration spectrum and the standard vibration amplitude corresponding to each frequency in the normal sound spectrum and standard sound amplitude ; Compare each vibration amplitude in turn With standard vibration amplitude , and the sound amplitude With standard sound amplitude The size relationship of

[0088] like , it means that the vibration amplitude under the corresponding frequency multiple does not exceed the standard vibration amplitude, that is, the vibration amplitude under the corresponding frequency multiple is within the normal range; if , it means that the vibration amplitude under the corresponding frequency multiple exceeds the standard vibration amplitude, that is, the vibration amplitude under the corresponding frequency multiple may be in the abnormal range, and the frequency multiple is placed in the vibration abnormal frequency multiple set; if , it means that the sound amplitude at the corresponding frequency exceeds the standard sound amplitude, that is, the sound amplitude at the corresponding frequency may be in the abnormal range, and the frequency is placed in the sound abnormal frequency set;

[0089] Step 306: Based on the frequency data in the vibration abnormal frequency set and the sound abnormal frequency set, calculate the Euclidean distance between the vibration amplitude at all frequencies and the standard vibration amplitude, and the Euclidean distance between the sound amplitude at all frequencies and the standard sound amplitude, and record them as vibration comprehensive difference values ​​respectively. And the overall difference of sound , the expression is:

[0090] ;

[0091] in, , Respectively represent the total number of data in the vibration abnormal multiple frequency set and the sound abnormal multiple frequency set, , They represent the abnormal vibration frequency concentration The vibration amplitude corresponding to each frequency multiple and the standard vibration amplitude; , They represent the abnormal frequency concentration of the sound. The sound amplitude corresponding to each octave and the standard sound amplitude.

[0092] When used, combine the contents in steps 301 to 306:

[0093] By triggering the abnormal monitoring instruction and opening the second monitoring point, the vibration and sound signals of the blades are analyzed in the frequency domain, and a spectrum comparison between abnormal and normal is established to effectively identify the abnormal frequency multiple set; combined with the comprehensive difference evaluation of vibration and sound, the system can more accurately judge the vibration abnormality of the engine blades, improve the accuracy of fault detection, and provide strong protection for the safe operation of the engine.

[0094] The abnormal judgment module combines the vibration comprehensive difference of each blade in each monitoring period. And the overall difference of sound , get the comprehensive abnormality judgment index of each leaf , and determine whether each blade has abnormal vibration; determine whether to trigger the generator stop command based on the number of blades with abnormal vibration; set up a buffer blade mechanism, and combine multiple monitoring cycles to further determine whether abnormal vibration occurs;

[0095] The abnormality judgment module includes the following steps:

[0096] Step 401: Calculate the vibration comprehensive difference obtained by the vibration data and sound data monitored in each monitoring cycle. And the overall difference of sound , get the comprehensive abnormality judgment index of each leaf , the expression is:

[0097] ;

[0098] in, , They represent the weight ratio coefficients of vibration data and sound data respectively. The specific values ​​are set by the generator management personnel. , ; , They represent the vibration comprehensive difference threshold and the sound comprehensive difference threshold respectively; the specific values ​​are also set by the generator management personnel according to specific needs; Indicates when When , the value in the brackets is 1; when When , the value in the brackets is ;

[0099] Step 402: If , then it means If a blade vibrates abnormally, , then it means No abnormal vibration occurred in the blades;

[0100] Count the number of blades with abnormal vibration in each monitoring cycle ,like , it means that there are too many blades with abnormal vibration in the current monitoring period, and the operation of the generator needs to be stopped to prevent the blades from being damaged. The generator stop command is triggered, and the RFID tags of the blades with abnormal vibration are sent to the engine management personnel;

[0101] like , it means that the number of blades with abnormal vibration in the current monitoring cycle is average, and further judgment is needed in combination with the abnormal judgment result of the next monitoring cycle, and the RFID tags of the blades with abnormal vibration in the current monitoring cycle are recorded and these blades are recorded as buffer blades;

[0102] If the number of blades with abnormal vibration in the next monitoring period is greater than or equal to , the generator stop command is triggered; if the number of blades with abnormal vibration in the next monitoring cycle is less than , it is determined whether there is a blade corresponding to the buffer blade recorded in the previous monitoring cycle among the abnormal blades. If so, an abnormal vibration alarm of the corresponding blade is sent to the generator manager; if not, the buffer blade recorded in the previous monitoring cycle is cleared, and the abnormal vibration blade monitored in the next monitoring cycle is marked as a buffer blade; the above analysis and design of the buffer blade is the buffer blade mechanism;

[0103] If no blade with abnormal vibration is detected in two consecutive monitoring cycles, the monitoring callback instruction is triggered to turn off and open the integrated sensor device at the second monitoring point on the casing.

[0104] When using, combine the contents in steps 401 to 402:

[0105] By comprehensively considering the comprehensive difference between vibration and sound, a comprehensive abnormality judgment index for blades was established, which achieved accurate identification of blade vibration abnormalities; the introduction of a buffer blade mechanism combined with data from multiple monitoring cycles for further judgment effectively reduced the false alarm rate and improved the reliability and stability of the system; this not only enables timely detection and processing of blade vibration abnormalities, but also automatically triggers corresponding processing instructions based on abnormal conditions, providing a strong guarantee for the safe operation of the engine.

[0106] refer to Figure 2 The present invention also provides a vibration test method for an engine blade, comprising:

[0107] Step 1: RFID tag each blade on the engine impeller; set a first monitoring point and a second monitoring point on the engine casing, respectively, and obtain vibration displacement data and sound signals at each monitoring point; when the engine is in normal operation, start monitoring the vibration displacement data at the first monitoring point;

[0108] Step 2: Record the vibration displacement data of each blade monitored in the time series diagram of the corresponding blade; calculate the average amplitude of the blade in a monitoring cycle based on the number of the first monitoring points, and combine the average amplitude of all blades to obtain the comprehensive average amplitude of the engine blade in each monitoring cycle. , and determine whether to trigger an abnormal monitoring instruction;

[0109] Step 3: When the abnormal monitoring instruction is triggered, the monitoring of the vibration displacement data and the sound signal at the first and second monitoring points is started; the vibration signals and sound signals of each blade monitored are analyzed in the frequency domain, and a comprehensive vibration spectrum diagram and a comprehensive sound spectrum diagram are established respectively; based on the magnitude relationship of the amplitude under the corresponding multiple frequency, a vibration abnormal multiple frequency set and a sound abnormal multiple frequency set are established respectively, and the vibration comprehensive difference is calculated respectively And the overall difference of sound ;

[0110] Step 4: Combine the comprehensive vibration difference of each blade in each monitoring cycle And the overall difference of sound , get the comprehensive abnormality judgment index of each leaf , and determine whether each blade has abnormal vibration; decide whether to trigger the generator stop command based on the number of blades with abnormal vibration; set up a buffer blade mechanism, and combine multiple monitoring cycles to further determine whether abnormal vibration occurs.

[0111] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer storage medium or transmitted via a computer storage medium.

[0112] Computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. Computer storage media can be any available media that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media. Available media can be magnetic media (e.g., floppy disks, hard disks, tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid state drives (SSDs)).

[0113] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A vibration test system for engine blades, characterized in that: include: The data acquisition module performs RFID tagging for each blade on the engine impeller; A first monitoring point and a second monitoring point are respectively set on the engine casing, and vibration displacement data and sound signals are obtained at each monitoring point; when the engine is in normal operation, the monitoring of the vibration displacement data at the first monitoring point is started; Each integrated sensor device is sequentially placed at the positions of 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315° on the upper edge of the casing; the integrated sensor devices at the positions of 0°, 90°, 180° and 270° on the upper edge of the casing are recorded as the first monitoring point, and the integrated sensor devices at the positions of 45°, 135°, 225° and 315° on the upper edge of the casing are recorded as the second monitoring point; The first abnormality monitoring module records the vibration displacement data of each blade monitored in a time series diagram of the corresponding blade; Based on the number of the first monitoring points, the average amplitude of the blade in a monitoring cycle is calculated, and the average amplitude of all blades is combined to obtain the comprehensive average amplitude Caa of the engine blade in each monitoring cycle, and determine whether to trigger an abnormal monitoring instruction; The second abnormality monitoring module, when the abnormality monitoring instruction is triggered, starts the monitoring of the vibration displacement data and the sound signal at the first and second monitoring points; performs frequency domain analysis on the vibration signals and sound signals of each blade monitored, and respectively establishes a comprehensive vibration spectrum diagram and a comprehensive sound spectrum diagram; establishes a vibration abnormal multiple frequency set and a sound abnormal multiple frequency set based on the magnitude relationship of the amplitude under the corresponding multiple frequency, and calculates the vibration comprehensive difference Vcd and the sound comprehensive difference Scd respectively; The abnormal judgment module combines the comprehensive vibration difference Vcd of each blade in each monitoring cycle i And the sound comprehensive difference Scd i , and obtain the comprehensive abnormality judgment index Cad of each blade i , and judge whether each blade has abnormal vibration; Whether to trigger the generator stop command is determined based on the number of blades with abnormal vibration; a buffer blade mechanism is set up, and multiple monitoring cycles are combined to further determine whether abnormal vibration occurs.

2. A vibration test system for engine blades as claimed in claim 1, characterized in that: When the blade enters the monitoring area of ​​the integrated sensor device, the RFID tag of the blade is identified, and the vibration displacement data of the blade is monitored; the monitored real-time vibration displacement data is recorded in the time series diagram of the corresponding blade; In one monitoring cycle, four consecutive vibration displacement-time change graphs will appear in the time series graph of each blade; the average amplitude in each vibration displacement-time change graph is calculated respectively, and then the four average amplitudes calculated based on the four vibration displacement-time change graphs of each blade are combined to obtain the average amplitude of each blade in each monitoring cycle.

3. A vibration test system for engine blades as claimed in claim 2, characterized in that: The average amplitudes of all blades in each monitoring cycle are combined to obtain the comprehensive average amplitude Caa of the engine blades in each monitoring cycle, which is expressed as: Where n represents the total number of blades of the engine, i represents the i-th blade of the engine, and j represents the j-th time passing through the integrated sensor device. It represents the time when the i-th blade enters the monitoring range of the integrated sensor device for the jth time in each monitoring cycle, represents the time when the i-th blade leaves the monitoring range of the integrated sensor device for the jth time in each monitoring cycle; |D(t)| represents the corresponding relationship between the absolute value of the vibration displacement and the time t in each vibration displacement-time variation diagram; Compare the comprehensive average amplitude Caa of each monitoring period with the comprehensive average amplitude threshold Caa0, wherein the comprehensive average amplitude threshold is k times the preset blade amplitude threshold, and 0<k<1; If Caa<Caa0, the abnormal monitoring instruction is not triggered; if Caa≥Caa0, the abnormal monitoring instruction is triggered.

4. A vibration test system for engine blades as claimed in claim 1, characterized in that: Obtain the real-time vibration displacement data and sound signal of each blade; arrange the monitored vibration displacement data in time series to construct the vibration signal of the blade; Perform Fourier transform on the vibration signal and sound signal of each blade, convert the time domain signal into frequency domain signal, and obtain the vibration spectrum and sound spectrum in 8 time periods respectively; For any blade, the vibration shift spectrum and sound spectrum in the eight time periods are averaged at the corresponding frequencies, and the calculated amplitude result is assigned to the corresponding frequency; based on the new amplitude after the average calculation at each frequency, the comprehensive vibration spectrum and comprehensive sound spectrum in each monitoring period are established; Obtain the vibration displacement data and sound signals corresponding to several time periods monitored during normal operation without any abnormality in the historical data, convert the time domain signals into frequency domain signals, and perform the mean operation of the amplitude at the same frequency in several time periods to obtain the normal vibration spectrum diagram and normal sound spectrum diagram.

5. A vibration test system for engine blades as claimed in claim 4, characterized in that: Starting from the lowest multiple frequency of the comprehensive vibration spectrum diagram and the comprehensive sound spectrum diagram, respectively, the vibration amplitude Va and the sound amplitude Sa corresponding to each multiple frequency in the comprehensive vibration spectrum diagram and the comprehensive sound spectrum diagram, as well as the standard vibration amplitude Va0 and the standard sound amplitude Sa0 corresponding to each multiple frequency in the normal vibration spectrum diagram and the normal sound spectrum diagram are obtained in sequence; If Va>Va0, it means that the vibration amplitude at the corresponding frequency exceeds the standard vibration amplitude, and the frequency is placed in the abnormal vibration frequency collection; if Sa>Sa0, it means that the sound amplitude at the corresponding frequency exceeds the standard sound amplitude, and the frequency is placed in the abnormal sound frequency collection.

6. A vibration test system for engine blades as claimed in claim 5, characterized in that: Based on the data of each frequency multiple in the abnormal vibration frequency multiple set and the abnormal sound frequency multiple set, the Euclidean distance between the vibration amplitude at all frequencies and the standard vibration amplitude, as well as the Euclidean distance between the sound amplitude at all frequencies and the standard sound amplitude are calculated, which are recorded as the vibration comprehensive difference Vcd and the sound comprehensive difference Scd, respectively, and the expressions are as follows: Among them, n1 and n2 represent the total number of data in the vibration abnormal multiple frequency set and the sound abnormal multiple frequency set, respectively. l , They represent the vibration amplitude corresponding to the lth frequency multiple in the vibration abnormal frequency multiple concentration and the standard vibration amplitude respectively; Sa l , They respectively represent the sound amplitude corresponding to the lth frequency in the abnormal sound frequency set and the standard sound amplitude.

7. A vibration test system for engine blades as claimed in claim 6, characterized in that: The vibration comprehensive difference Vcd calculated in each monitoring cycle i And the sound comprehensive difference Scd i Combined, the comprehensive abnormality judgment index Cad of each blade is obtained i , the expression is: Among them, λ1 and λ2 represent the weight ratio coefficients of vibration data and sound data respectively, and the specific values ​​are set by the generator management personnel, and λ1+λ2=1, λ1>λ2; Vcd0 and Scd0 represent the vibration comprehensive difference threshold and the sound comprehensive difference threshold respectively; Indicates when When , the value in the brackets is 1; when When , the value in the brackets is 8. A vibration test system for engine blades as claimed in claim 7, characterized in that: If Cad i ≥1.2, it means that the i-th blade has abnormal vibration; if Cad i <1.2, it means that the i-th blade has no abnormal vibration; Count the number of blades with abnormal vibration in each monitoring cycle. Then the generator stop command is triggered; like Then, further judgment is made in combination with the abnormal judgment result of the next monitoring cycle, and the RFID tags of the blades with abnormal vibration in the current monitoring cycle are recorded and these blades are recorded as buffer blades; If the number of blades with abnormal vibration in the next monitoring period is greater than or equal to The generator stop command is triggered; if the number of blades with abnormal vibration in the next monitoring cycle is less than It is determined whether there is a blade corresponding to the buffer blade recorded in the previous monitoring cycle among the abnormal blades. If there is, an abnormal vibration alarm of the corresponding blade is sent to the generator management personnel; If it does not exist, the buffer blade recorded in the previous monitoring cycle is cleared, and the blade with abnormal vibration detected in the next monitoring cycle is marked as a buffer blade; If no blade with abnormal vibration is detected in two consecutive monitoring cycles, the monitoring callback instruction is triggered.

9. A vibration test method for engine blades, characterized in that: include: Step 1: RFID tag each blade on the engine impeller; A first monitoring point and a second monitoring point are respectively set on the engine casing, and vibration displacement data and sound signals are obtained at each monitoring point; when the engine is in normal operation, the monitoring of the vibration displacement data at the first monitoring point is started; Each integrated sensor device is sequentially placed at the positions of 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315° on the upper edge of the casing; the integrated sensor devices at the positions of 0°, 90°, 180° and 270° on the upper edge of the casing are recorded as the first monitoring point, and the integrated sensor devices at the positions of 45°, 135°, 225° and 315° on the upper edge of the casing are recorded as the second monitoring point; Step 2: Record the monitored vibration displacement data of each blade in a time series diagram of the corresponding blade; Based on the number of the first monitoring points, the average amplitude of the blade in a monitoring cycle is calculated, and the average amplitude of all blades is combined to obtain the comprehensive average amplitude Caa of the engine blade in each monitoring cycle, and determine whether to trigger an abnormal monitoring instruction; Step 3: When the abnormal monitoring instruction is triggered, the monitoring of the vibration displacement data and the sound signal at the first and second monitoring points is started; the vibration signals and sound signals of each blade monitored are analyzed in the frequency domain, and a comprehensive vibration spectrum diagram and a comprehensive sound spectrum diagram are established respectively; based on the magnitude relationship of the amplitude under the corresponding multiple frequency, a vibration abnormal multiple frequency set and a sound abnormal multiple frequency set are established respectively, and the vibration comprehensive difference Vcd and the sound comprehensive difference Scd are calculated respectively; Step 4: Combine the vibration comprehensive difference Vcd of each blade in each monitoring cycle i And the sound comprehensive difference Scd i , and obtain the comprehensive abnormality judgment index Cad of each blade i , and judge whether each blade has abnormal vibration; Whether to trigger the generator stop command is determined based on the number of blades with abnormal vibration; a buffer blade mechanism is set up, and multiple monitoring cycles are combined to further determine whether abnormal vibration occurs.

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