An adaptive oil film vortex fault monitoring method, device and equipment

Abstract

The present invention discloses a self-adaptive monitoring method, device and equipment for oil film vortex fault, including obtaining vibration signals and rotor speeds of the unit under different working conditions; performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum; obtaining the amplitude-frequency variation under different working conditions from the envelope spectrum; calculating the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude according to the amplitude-frequency variation and the rotor speed, and obtaining the alarm threshold of the unit; when the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, automatically alarming, and analyzing whether a false alarm occurs, and raising the alarm threshold when a false alarm occurs; otherwise analyzing whether a missed alarm occurs, and lowering the alarm threshold when a missed alarm occurs. By adopting the embodiments of the present invention, the fault monitoring deviation caused by the uncertainty of the characteristic frequency can be reduced, and the alarm threshold can be adjusted adaptively to achieve accurate fault monitoring.

Description

Technical Field

[0001] The invention relates to the field of oil film vortex fault troubleshooting, and in particular to an adaptive oil film vortex fault monitoring method, device and equipment. Background Art

[0002] Due to the demand for high speed of rotating machinery in social industrial production, oil film vortex, oil film oscillation and other fault phenomena frequently occur in rotating machinery. Most of the major accidents of large rotating machinery and equipment are caused by low-frequency vibration instability, and oil film vortex failure is one of the common rotor failures.

[0003] The oil film turbulence fault signals under actual working conditions are usually nonlinear, non-stationary multi-component signals, whose frequency components change with time. The existing technology mainly relies on expert knowledge and manual analysis, which requires a lot of time and energy for data analysis, and cannot timely and conveniently, stably and reliably diagnose the fault conditions. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an adaptive oil film turbulence fault monitoring method, device and equipment, which can reduce the time cost of manual analysis, reduce the fault monitoring deviation caused by untimely fault detection and characteristic frequency uncertainty, and can adaptively adjust the alarm threshold to obtain accurate oil film turbulence fault monitoring results by analyzing the unit data under different operating conditions, setting the unit's alarm threshold, and dynamically adjusting the alarm threshold.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides an adaptive oil film vortex fault monitoring method, comprising:

[0006] Obtaining vibration signals and rotor speeds of the unit under different operating conditions; the different operating conditions include normal operating conditions and abnormal operating conditions;

[0007] Performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum;

[0008] Analyzing the envelope spectrum, and obtaining amplitude-frequency changes under different working conditions from the envelope spectrum;

[0009] According to the amplitude-frequency variation and the rotor speed, the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude is calculated to obtain the alarm threshold of the unit;

[0010] When the ratio of the oil film turbulence frequency to the rotational frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued, and an analysis is made as to whether a false alarm occurs. If a false alarm occurs, the alarm threshold is raised; otherwise, an analysis is made as to whether a missed alarm occurs. If a missed alarm occurs, the alarm threshold is lowered.

[0011] As an improvement of the above solution, performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum includes:

[0012] pass Perform Hilbert transform on the vibration signal; wherein x(t) is the vibration signal, * is the convolution, is the Hilbert transform of the vibration signal;

[0013] pass Generate an analytical signal of the vibration signal; wherein z(t) is the analytical signal,

[0014] Performing modulus calculation on the analytical signal to obtain the envelope of the vibration signal;

[0015] Performing Fourier transform on the envelope to generate an envelope spectrum.

[0016] As an improvement of the above scheme, the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude is calculated according to the amplitude-frequency change and the rotor speed to obtain the alarm threshold of the unit, including:

[0017] According to the rotor speed, a theoretical rotation frequency value and a theoretical oil film vortex frequency value are obtained;

[0018] According to the amplitude-frequency variation, a first characteristic frequency window is set at the theoretical frequency conversion value, and the maximum amplitude of the first characteristic frequency window is used as the frequency conversion amplitude;

[0019] According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value; and the maximum amplitude of the second characteristic frequency window is used as the oil film vortex frequency amplitude;

[0020] The ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude is calculated to obtain the alarm threshold of the unit.

[0021] As an improvement of the above scheme, when the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued, and an analysis is made as to whether a false alarm occurs. If a false alarm occurs, the alarm threshold is raised; otherwise, an analysis is made as to whether a missed alarm occurs. If a missed alarm occurs, the alarm threshold is lowered, including:

[0022] When the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued. When the number of automatic alarms within a fixed time is greater than the preset number threshold and the unit has not failed, it is considered a false alarm and the alarm threshold is increased by 10%;

[0023] When the ratio of the oil film vortex frequency to the rotational frequency during the operation of the unit is not greater than the alarm threshold, when a fault occurs in the unit, it is considered that a missed alarm occurs, and the alarm threshold is lowered by 10%.

[0024] As an improvement of the above solution, the theoretical rotational frequency value and the theoretical oil film vortex frequency value are obtained according to the rotor speed, including:

[0025] By f r =v t / 60 to calculate the theoretical frequency value; where v t is the rotor speed; f r is the theoretical rotation frequency value;

[0026] By f n =f r ×α to calculate the theoretical oil film vortex frequency value; where f r is the theoretical frequency value; α=0.5; f n is the theoretical oil film vortex frequency value.

[0027] As an improvement of the above solution, according to the amplitude-frequency change, a first characteristic frequency window is set at the theoretical frequency conversion value, and the maximum amplitude of the first characteristic frequency window is used as the frequency conversion amplitude, including:

[0028] According to the amplitude-frequency change, a first characteristic frequency window is set at the theoretical frequency conversion value. satisfy Among them, f r is the theoretical rotation frequency value;

[0029] The maximum amplitude of the first characteristic frequency window is calculated and used as the rotation frequency amplitude.

[0030] As an improvement of the above scheme, according to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value; and the maximum amplitude of the second characteristic frequency window is used as the oil film vortex frequency amplitude, including:

[0031] According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value. satisfy Among them, f n is the theoretical oil film vortex characteristic frequency;

[0032] The maximum amplitude of the second characteristic frequency window is calculated and used as the oil film vortex frequency amplitude.

[0033] The embodiment of the present invention further provides an adaptive oil film vortex fault monitoring device, comprising:

[0034] A unit data acquisition module, used to acquire the vibration signal and rotor speed of the unit under different working conditions; the different working conditions include normal working conditions and abnormal working conditions;

[0035] An envelope spectrum generating module, used for performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum;

[0036] An amplitude-frequency variation generation module is used to analyze the envelope spectrum and obtain the amplitude-frequency variation under different working conditions from the envelope spectrum;

[0037] An alarm threshold calculation module is used to calculate the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude according to the amplitude-frequency change and the rotor speed, so as to obtain the alarm threshold of the unit;

[0038] The alarm threshold adjustment module is used to automatically alarm when the ratio of the oil film turbulence frequency to the rotational frequency during the operation of the unit is greater than the alarm threshold, and analyze whether a false alarm occurs. If a false alarm occurs, the alarm threshold is increased; otherwise, it is analyzed whether a missed alarm occurs, and the alarm threshold is lowered if a missed alarm occurs.

[0039] As an improvement of the above solution, performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum includes:

[0040] pass Perform Hilbert transform on the vibration signal; wherein x(t) is the vibration signal, * is the convolution, is the Hilbert transform of the vibration signal;

[0041] pass Generate an analytical signal of the vibration signal; wherein z(t) is the analytical signal,

[0042] Performing modulus calculation on the analytical signal to obtain the envelope of the vibration signal;

[0043] Performing Fourier transform on the envelope to generate an envelope spectrum.

[0044] An embodiment of the present invention also provides an adaptive oil film turbulence fault monitoring device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements any one of the adaptive oil film turbulence fault monitoring methods described above.

[0045] Compared with the prior art, the present invention discloses an adaptive monitoring method for oil film vortex fault, which obtains the vibration signal and rotor speed of the unit under different working conditions; the different working conditions include normal working conditions and abnormal working conditions; the vibration signal is subjected to Hilbert transformation, the envelope of the vibration signal is extracted, and an envelope spectrum is generated; the envelope spectrum is analyzed, and the amplitude-frequency variation under different working conditions is obtained from the envelope spectrum; according to the amplitude-frequency variation and the rotor speed, the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude is calculated to obtain the alarm threshold of the unit; when the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued, and whether a false alarm occurs is analyzed, and when a false alarm occurs, the alarm threshold is increased; otherwise, whether a missed alarm occurs is analyzed, and when a missed alarm occurs, the alarm threshold is lowered. The embodiment of the present invention can reduce the time cost of manual analysis, reduce the fault monitoring deviation caused by untimely fault detection and characteristic frequency uncertainty, and can adaptively adjust the alarm threshold to accurately monitor oil film vortex faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the steps of a method for monitoring an adaptive oil film vortex fault provided by an embodiment of the present invention;

[0047] Figure 2 is a schematic diagram of the rotor speed under normal working conditions provided by an embodiment of the present invention;

[0048] Figure 3 is a schematic diagram of the rotor speed under abnormal conditions provided by an embodiment of the present invention;

[0049] Figure 4 is a schematic diagram of amplitude-frequency variation under normal working conditions provided by an embodiment of the present invention;

[0050] Figure 5 is a schematic diagram of amplitude-frequency variation under abnormal working conditions provided by an embodiment of the present invention;

[0051] Figure 6 Schematic diagram of the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude and the alarm threshold under normal working conditions provided by an embodiment of the present invention;

[0052] Figure 7 Schematic diagram of the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude and the alarm threshold under abnormal working conditions provided by an embodiment of the present invention;

[0053] Figure 8 It is a structural schematic diagram of an adaptive oil film vortex fault monitoring device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0054] 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.

[0055] In the description of the specification and claims, it is to be understood that the terms first, second, etc. in the specification and claims are only used for the purpose of describing the same technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, nor necessarily describing the order or time sequence. The terms are interchangeable where appropriate. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0056] The rotor system supported by the bearing often experiences oil film vortex and oil film oscillation failures, which are a kind of self-excited vibration caused by nonlinear oil film force. However, since the oil film vortex failure is affected by nonlinear factors, the oil film instability theory in the prior art is still imperfect. Monitoring the oil film vortex failure requires determining the monitoring indicators and the alarm thresholds of the indicators. At present, there is no systematic method that can accurately monitor the oil film vortex failure.

[0057] See also Figure 1 , is a schematic flow chart of the steps of an adaptive oil film vortex fault monitoring method provided by an embodiment of the present invention. In this embodiment, the adaptive oil film vortex fault monitoring is specifically performed through steps S1 to S5: S1, obtaining the vibration signal and rotor speed of the unit under different working conditions; the different working conditions include normal working conditions and abnormal working conditions.

[0058] S2. Performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum.

[0059] S3. Analyze the envelope spectrum, and obtain the amplitude-frequency variation under different working conditions from the envelope spectrum.

[0060] S4. Calculate the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude according to the amplitude-frequency variation and the rotor speed, and obtain the alarm threshold of the unit.

[0061] S5. When the ratio of the oil film turbulence frequency to the rotational frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically triggered, and an analysis is performed to determine whether a false alarm occurs. If a false alarm occurs, the alarm threshold is raised; otherwise, an analysis is performed to determine whether a missed alarm occurs. If a missed alarm occurs, the alarm threshold is lowered.

[0062] It should be noted that step S1, obtaining the vibration signal and rotor speed of the unit under different working conditions can be obtained by performing unit testing, or by obtaining an existing data set, and the specific source of the unit data does not affect the beneficial effects achieved by the present invention.

[0063] As a preferred implementation manner, performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum includes:

[0064] pass Perform Hilbert transform on the vibration signal; wherein x(t) is the vibration signal, * is the convolution, is the Hilbert transform of the vibration signal;

[0065] pass Generate an analytical signal of the vibration signal; wherein z(t) is the analytical signal, Performing modulus calculation on the analytical signal to obtain the envelope of the vibration signal;

[0066] Performing Fourier transform on the envelope to generate an envelope spectrum.

[0067] It can be understood that the Hilbert transform can be used to calculate the instantaneous phase and instantaneous frequency of the signal, which is of great significance for the signal analysis that needs to be processed in the frequency domain and time domain. In an embodiment of the present invention, the vibration signal is subjected to the Hilbert transform to obtain an analytical signal, the real part of which is the original signal, and the imaginary part is the Hilbert transform pair; the envelope of the signal can be obtained by modulo the analytical signal, and the envelope can be used to represent the mechanical vibration characteristics, which includes the low-frequency, high-amplitude components in the vibration signal and sudden events, such as fault impact and other information, but the vibration characteristics obtained only by the envelope are not sufficient to fully characterize the characteristics when the oil film vortex fault occurs and the indicators of the unit operating conditions.

[0068] In the above scheme, the resonance demodulation method is used to effectively demodulate the non-stationary signal, which well describes the spectrum characteristics of the non-stationary signal and has the beneficial effects of strong anti-interference ability and high signal-to-noise ratio. The envelope is Fourier transformed, and the horizontal axis of the generated envelope spectrum represents the frequency and the vertical axis represents the amplitude, which reflects the signal energy in different frequency bands and can be used to diagnose the condition of the unit.

[0069] As a preferred implementation, the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude is calculated according to the amplitude-frequency variation and the rotor speed to obtain the alarm threshold of the unit, including:

[0070] According to the rotor speed, a theoretical rotation frequency value and a theoretical oil film vortex frequency value are obtained;

[0071] According to the amplitude-frequency variation, a first characteristic frequency window is set at the theoretical frequency conversion value, and the maximum amplitude of the first characteristic frequency window is used as the frequency conversion amplitude;

[0072] According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value; and the maximum amplitude of the second characteristic frequency window is used as the oil film vortex frequency amplitude;

[0073] The ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude is calculated to obtain the alarm threshold of the unit.

[0074] In the above scheme, the amplitude ratio constructed by the oil film vortex frequency amplitude and the rotation frequency amplitude is used as an indicator for characterizing the operating condition of the unit, and the alarm threshold of the unit is obtained by analyzing the data of different working conditions. Based on the oil film vortex theory and the analysis of the unit data under different working conditions, the embodiment of the present invention provides indicators and thresholds that can be used to characterize oil film vortex faults, and applies them to the monitoring of oil film vortex faults. Compared with the prior art, it can reduce the time cost of manual analysis and reduce the fault monitoring deviation caused by untimely fault detection and the influence of characteristic frequency uncertainty.

[0075] Further, preferably, obtaining a theoretical rotational frequency value and a theoretical oil film vortex frequency value according to the rotor speed includes:

[0076] By f r =v t / 60 to calculate the theoretical frequency value; where v t is the rotor speed; f r is the theoretical rotation frequency value;

[0077] By f n =f r ×α to calculate the theoretical oil film vortex frequency value; where f r is the theoretical frequency value; α=0.5; f n is the theoretical oil film vortex frequency value.

[0078] Preferably, the step of setting a first characteristic frequency window at the theoretical frequency conversion value according to the amplitude-frequency variation and taking the maximum amplitude of the first characteristic frequency window as the frequency conversion amplitude comprises:

[0079] According to the amplitude-frequency change, a first characteristic frequency window is set at the theoretical frequency conversion value. satisfy Among them, f r is the theoretical rotation frequency value;

[0080] The maximum amplitude of the first characteristic frequency window is calculated and used as the rotation frequency amplitude.

[0081] Preferably, the step of setting a second characteristic frequency window at the theoretical oil film vortex frequency value according to the amplitude-frequency variation; and taking the maximum amplitude of the second characteristic frequency window as the oil film vortex frequency amplitude includes:

[0082] According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value. satisfy Among them, f n is the theoretical oil film vortex frequency value;

[0083] The maximum amplitude of the second characteristic frequency window is calculated and used as the oil film vortex frequency amplitude.

[0084] It should be noted that in the oil film vortex theory, it is believed that the vibration frequency of the oil film vortex is equal to half of the rotor speed, while in actual applications, the vibration frequency of the oil film vortex is about 0.42 to 0.48 times the rotor speed, that is, if half of the rotor speed is used as the vibration frequency of the oil film vortex for subsequent calculations, errors will occur in the results, but there is uncertainty in the vibration frequency. In an embodiment of the present invention, by setting a first characteristic frequency window at the theoretical rotation frequency value, setting a second characteristic frequency window at the theoretical oil film vortex characteristic frequency, and selecting the maximum amplitude from the characteristic frequency window as the characteristic value, the deviation caused by the uncertainty of the characteristic frequency can be eliminated as much as possible, and the impact of minor faults caused by external interference or self-component failure can be reduced.

[0085] As a preferred implementation, when the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued, and an analysis is performed to determine whether a false alarm occurs. If a false alarm occurs, the alarm threshold is raised; otherwise, an analysis is performed to determine whether a missed alarm occurs. If a missed alarm occurs, the alarm threshold is lowered, including:

[0086] When the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued. When the number of automatic alarms within a fixed time is greater than the preset number threshold and the unit has not failed, it is considered a false alarm and the alarm threshold is increased by 10%;

[0087] When the ratio of the oil film vortex frequency to the rotational frequency during the operation of the unit is not greater than the alarm threshold, when a fault occurs in the unit, it is considered that a missed alarm occurs, and the alarm threshold is lowered by 10%.

[0088] It should be noted that raising or lowering the alarm threshold by 10% according to whether a false alarm or missed alarm occurs is only an example. In actual applications, other adjustment values ​​can also be set according to the monitored units. The specific settings of the adjustment values ​​do not affect the beneficial effects achieved by the present invention.

[0089] In the above scheme, during the actual operation of the unit, the alarm threshold may change with the usage of the components of the unit, the service life, etc. The embodiment of the present invention proposes to adaptively adjust the alarm threshold by monitoring whether there is a false alarm or a missed alarm, without the need for manual intervention.

[0090] As an example, in an embodiment of the present invention, the vibration signal and rotor speed of the unit under different working conditions are obtained by obtaining the data set of Shenyang Blower Group Measurement and Control Technology Co., Ltd. The data set includes a variety of different types of units such as large steam turbines, generators, compressors, as well as data samples under normal working conditions and data samples under abnormal working conditions of the unit. Specifically, the data sample of the unit of Shenyang Blower Group-isooctane device-refrigerant compressor-turbine-gearbox unit is used. The gearbox has four measuring point positions, namely motor side vibration X, motor side vibration Y, compressor side vibration X, and compressor side vibration Y. The system sampling interval is once every five minutes. The vibration displacement of the measuring point of the unit is collected by the displacement sensor, and the relevant time, frequency, speed, waveform data, etc. collected at the current moment are saved in a txt file, where the waveform data is 1024 sampling points each time. A measuring point data set of the gear compressor measuring vibration X is selected as the unit data, and an adaptive oil film vortex fault monitoring method provided by an embodiment of the present invention is adopted.

[0091] See also Figure 2 and Figure 3 , are the rotor speed data under normal working conditions and abnormal working conditions, respectively. Select a certain moment when the rotor speed is under normal working conditions and abnormal working conditions for frequency domain analysis, perform Hilbert transform on the obtained vibration signal to obtain the envelope signal, and then perform Fourier transform to obtain the envelope spectrum of the signal. According to the envelope spectrum, it can be obtained Figure 4 and Figure 5 The amplitude-frequency changes under normal and abnormal conditions are shown in the figure. Figure 4 and Figure 5 It can be seen that when the unit is in normal working conditions, the amplitude near the rotor speed will be relatively large, and there will be related frequency multiples later; when the unit is in abnormal working conditions, the amplitude near the rotor speed is small, but a larger amplitude appears near 1 / 2 times the rotor speed, which is close to the theoretically calculated oil film vortex frequency value, and it is further judged that an oil film vortex fault has occurred.

[0092] According to the rotor speed, a theoretical rotation frequency value and a theoretical oil film vortex frequency value are calculated; according to the amplitude-frequency change, a first characteristic frequency window is set at the theoretical rotation frequency value, and the first characteristic frequency window satisfy Among them, f ris the theoretical rotation frequency value; the maximum amplitude of the first characteristic frequency window is calculated and used as the rotation frequency amplitude; according to the amplitude-frequency change, a second characteristic frequency window is set at the theoretical oil film vortex frequency value, and the second characteristic frequency window satisfy Among them, f n is the theoretical oil film vortex frequency value; calculate the maximum amplitude of the second characteristic frequency window and use it as the oil film vortex frequency amplitude; calculate the ratio of the oil film vortex frequency amplitude to the speed amplitude to obtain the alarm threshold of the unit. Figure 6 and Figure 7 , are schematic diagrams of the ratio of the oil film vortex frequency amplitude to the speed frequency amplitude and the alarm threshold under normal and abnormal conditions, respectively. Analysis shows that under normal conditions, the oil film vortex frequency amplitude and the speed frequency amplitude are small and stable; under abnormal conditions, the oil film vortex frequency amplitude and the speed frequency amplitude are large and unstable. In an embodiment of the present invention, the alarm threshold of the oil film vortex is set to 4, and an alarm is triggered when the ratio of the oil film vortex frequency amplitude to the speed frequency amplitude is greater than 4 during the operation of the unit.

[0093] When the ratio of the oil film turbulence frequency to the rotational frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued. When the number of automatic alarms within a fixed time is greater than the preset threshold and the unit has not failed, it is considered a false alarm and the alarm threshold is increased by 10%; when the ratio of the oil film turbulence frequency to the rotational frequency during the operation of the unit is not greater than the alarm threshold, when the unit has failed, it is considered a missed alarm and the alarm threshold is lowered by 10%.

[0094] The adaptive oil film vortex fault monitoring method provided by the embodiment of the present invention can reduce the time cost of manual analysis, reduce the fault monitoring deviation caused by untimely fault detection and characteristic frequency uncertainty, and can adaptively adjust the alarm threshold to accurately monitor oil film vortex faults.

[0095] See also Figure 8 , Figure 8 1 is a schematic diagram of the structure of an adaptive oil film vortex fault monitoring device provided by an embodiment of the present invention. The adaptive oil film vortex fault monitoring device comprises a unit data acquisition module 11, an envelope spectrum generation module 12, an amplitude-frequency change situation generation module 13, an alarm threshold calculation module 14 and an alarm threshold adjustment module 15; wherein:

[0096] The unit data acquisition module 11 is used to obtain the vibration signal and rotor speed of the unit under different working conditions; the different working conditions include normal working conditions and abnormal working conditions;

[0097] An envelope spectrum generating module 12 is used to perform Hilbert transform on the vibration signal, extract the envelope of the vibration signal, and generate an envelope spectrum;

[0098] An amplitude-frequency variation generation module 13 is used to analyze the envelope spectrum and obtain the amplitude-frequency variation under different working conditions from the envelope spectrum;

[0099] An alarm threshold calculation module 14 is used to calculate the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude according to the amplitude-frequency variation and the rotor speed, so as to obtain the alarm threshold of the unit;

[0100] The alarm threshold adjustment module 15 is used to automatically alarm when the ratio of the oil film turbulence frequency to the rotational frequency during the operation of the unit is greater than the alarm threshold, and analyze whether a false alarm occurs. If a false alarm occurs, the alarm threshold is increased; otherwise, it is analyzed whether a missed alarm occurs, and the alarm threshold is lowered if a missed alarm occurs.

[0101] As a preferred implementation manner, performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum includes:

[0102] pass Perform Hilbert transform on the vibration signal; wherein x(t) is the vibration signal, * is the convolution, is the Hilbert transform of the vibration signal;

[0103] pass Generate an analytical signal of the vibration signal; wherein z(t) is the analytical signal, Performing modulus calculation on the analytical signal to obtain the envelope of the vibration signal;

[0104] Performing Fourier transform on the envelope to generate an envelope spectrum.

[0105] As a preferred implementation, the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude is calculated according to the amplitude-frequency variation and the rotor speed to obtain the alarm threshold of the unit, including:

[0106] According to the rotor speed, a theoretical rotation frequency value and a theoretical oil film vortex frequency value are obtained;

[0107] According to the amplitude-frequency variation, a first characteristic frequency window is set at the theoretical frequency conversion value, and the maximum amplitude of the first characteristic frequency window is used as the frequency conversion amplitude;

[0108] According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value; and the maximum amplitude of the second characteristic frequency window is used as the oil film vortex frequency amplitude;

[0109] The ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude is calculated to obtain the alarm threshold of the unit.

[0110] Further, preferably, obtaining a theoretical rotational frequency value and a theoretical oil film vortex frequency value according to the rotor speed includes:

[0111] By f r =v t / 60 to calculate the theoretical frequency value; where v t is the rotor speed; f r is the theoretical rotation frequency value;

[0112] By f n =f r ×α to calculate the theoretical oil film vortex frequency; where f r is the theoretical frequency value; α=0.5; f n is the theoretical oil film vortex frequency.

[0113] Preferably, the step of setting a first characteristic frequency window at the theoretical frequency conversion value according to the amplitude-frequency variation and taking the maximum amplitude of the first characteristic frequency window as the frequency conversion amplitude comprises:

[0114] According to the amplitude-frequency change, a first characteristic frequency window is set at the theoretical frequency conversion value. satisfy Among them, f r is the theoretical rotation frequency value;

[0115] The maximum amplitude of the first characteristic frequency window is calculated and used as the rotation frequency amplitude.

[0116] Preferably, the step of setting a second characteristic frequency window at the theoretical oil film vortex frequency value according to the amplitude-frequency variation; and taking the maximum amplitude of the second characteristic frequency window as the oil film vortex frequency amplitude includes:

[0117] According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value. satisfy Among them, f n is the theoretical oil film vortex frequency value;

[0118] The maximum amplitude of the second characteristic frequency window is calculated and used as the oil film vortex frequency amplitude.

[0119] As a preferred implementation, when the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued, and an analysis is performed to determine whether a false alarm occurs. If a false alarm occurs, the alarm threshold is raised; otherwise, an analysis is performed to determine whether a missed alarm occurs. If a missed alarm occurs, the alarm threshold is lowered, including:

[0120] When the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued. When the number of automatic alarms within a fixed time is greater than the preset number threshold and the unit has not failed, it is considered a false alarm and the alarm threshold is increased by 10%;

[0121] When the ratio of the oil film vortex frequency to the rotational frequency during the operation of the unit is not greater than the alarm threshold, when a fault occurs in the unit, it is considered that a missed alarm occurs, and the alarm threshold is lowered by 10%.

[0122] An adaptive oil film vortex fault monitoring device provided by an embodiment of the present invention can reduce the time cost of manual analysis, reduce fault monitoring deviations caused by untimely fault detection and characteristic frequency uncertainty, and can adaptively adjust the alarm threshold to accurately monitor oil film vortex faults.

[0123] An embodiment of the present invention also provides an adaptive oil film turbulence fault monitoring device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements an adaptive oil film turbulence fault monitoring method as described above. The working principles and beneficial effects of the two correspond one to one, and thus will not be elaborated upon.

[0124] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0125] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An adaptive oil film vortex fault monitoring method, characterized in that: include: Obtaining vibration signals and rotor speeds of the unit under different operating conditions; the different operating conditions include normal operating conditions and abnormal operating conditions; Performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum; Analyzing the envelope spectrum, and obtaining amplitude-frequency changes under different working conditions from the envelope spectrum; According to the amplitude-frequency variation and the rotor speed, the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude is calculated to obtain the alarm threshold of the unit; When the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued, and an analysis is performed to determine whether a false alarm occurs. If a false alarm occurs, the alarm threshold is raised; otherwise, an analysis is performed to determine whether a missed alarm occurs. If a missed alarm occurs, the alarm threshold is lowered. The calculating the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude according to the amplitude-frequency variation and the rotor speed to obtain the alarm threshold of the unit includes: According to the rotor speed, a theoretical rotation frequency value and a theoretical oil film vortex frequency value are obtained; According to the amplitude-frequency variation, a first characteristic frequency window is set at the theoretical frequency conversion value, and the maximum amplitude of the first characteristic frequency window is used as the frequency conversion amplitude; According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value; and the maximum amplitude of the second characteristic frequency window is used as the oil film vortex frequency amplitude; Calculate the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude to obtain the alarm threshold of the unit; The obtaining of a theoretical rotation frequency value and a theoretical oil film vortex frequency value according to the rotor speed includes: pass The theoretical frequency value is calculated; among them, is the rotor speed; is the theoretical rotation frequency value; pass The theoretical oil film vortex frequency value is calculated; where: is the theoretical rotation frequency value; ; is the theoretical oil film vortex frequency value; The step of setting a first characteristic frequency window at the theoretical frequency conversion value according to the amplitude-frequency change, and taking the maximum amplitude of the first characteristic frequency window as the frequency conversion amplitude, comprises: According to the amplitude-frequency change, a first characteristic frequency window is set at the theoretical frequency conversion value. satisfy ;in, is the theoretical rotation frequency value; Calculate the maximum amplitude of the first characteristic frequency window and use it as the frequency conversion amplitude; The method of setting a second characteristic frequency window at the theoretical oil film vortex frequency value according to the amplitude-frequency variation; and taking the maximum amplitude of the second characteristic frequency window as the oil film vortex frequency amplitude includes: According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value. satisfy ;in, is the theoretical oil film vortex frequency value; Calculating the maximum amplitude of the second characteristic frequency window and using it as the oil film vortex frequency amplitude; When the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued, and an analysis is performed to determine whether a false alarm occurs. If a false alarm occurs, the alarm threshold is raised; otherwise, an analysis is performed to determine whether a missed alarm occurs. If a missed alarm occurs, the alarm threshold is lowered, including: When the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued. When the number of automatic alarms within a fixed time is greater than the preset number threshold and the unit has not failed, it is considered that a false alarm has occurred and the alarm threshold is raised; When the ratio of the oil film turbulence frequency to the rotational frequency during the operation of the unit is not greater than the alarm threshold, when a fault occurs in the unit, it is considered that a missed alarm occurs and the alarm threshold is lowered.

2. The adaptive oil film vortex fault monitoring method according to claim 1, characterized in that: The step of performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum comprises: pass , perform Hilbert transform on the vibration signal; wherein x(t) is the vibration signal, * is the convolution, is the Hilbert transform of the vibration signal; pass Generate an analytical signal of the vibration signal; wherein z(t) is the analytical signal, ; Performing modulus calculation on the analytical signal to obtain the envelope of the vibration signal; Performing Fourier transform on the envelope to generate an envelope spectrum.

3. An adaptive oil film vortex fault monitoring device, characterized in that: include: A unit data acquisition module, used to acquire the vibration signal and rotor speed of the unit under different working conditions; the different working conditions include normal working conditions and abnormal working conditions; An envelope spectrum generating module, used for performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum; An amplitude-frequency variation generation module is used to analyze the envelope spectrum and obtain the amplitude-frequency variation under different working conditions from the envelope spectrum; An alarm threshold calculation module is used to calculate the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude according to the amplitude-frequency change and the rotor speed, so as to obtain the alarm threshold of the unit; The alarm threshold adjustment module is used to automatically alarm when the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, and analyze whether a false alarm occurs. If a false alarm occurs, the alarm threshold is increased; otherwise, it is analyzed whether a missed alarm occurs, and if a missed alarm occurs, the alarm threshold is lowered; The calculating the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude according to the amplitude-frequency variation and the rotor speed to obtain the alarm threshold of the unit includes: According to the rotor speed, a theoretical rotation frequency value and a theoretical oil film vortex frequency value are obtained; According to the amplitude-frequency variation, a first characteristic frequency window is set at the theoretical frequency conversion value, and the maximum amplitude of the first characteristic frequency window is used as the frequency conversion amplitude; According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value; and the maximum amplitude of the second characteristic frequency window is used as the oil film vortex frequency amplitude; Calculate the ratio of the oil film vortex frequency amplitude to the rotation frequency amplitude to obtain the alarm threshold of the unit; The obtaining of a theoretical rotation frequency value and a theoretical oil film vortex frequency value according to the rotor speed includes: pass The theoretical frequency value is calculated; among them, is the rotor speed; is the theoretical rotation frequency value; pass The theoretical oil film vortex frequency value is calculated; where: is the theoretical rotation frequency value; ; is the theoretical oil film vortex frequency value; The step of setting a first characteristic frequency window at the theoretical frequency conversion value according to the amplitude-frequency change, and taking the maximum amplitude of the first characteristic frequency window as the frequency conversion amplitude, comprises: According to the amplitude-frequency change, a first characteristic frequency window is set at the theoretical frequency conversion value. satisfy ;in, is the theoretical rotation frequency value; Calculate the maximum amplitude of the first characteristic frequency window and use it as the frequency conversion amplitude; The method of setting a second characteristic frequency window at the theoretical oil film vortex frequency value according to the amplitude-frequency variation; and taking the maximum amplitude of the second characteristic frequency window as the oil film vortex frequency amplitude includes: According to the amplitude-frequency variation, a second characteristic frequency window is set at the theoretical oil film vortex frequency value. satisfy ;in, is the theoretical oil film vortex frequency value; Calculating the maximum amplitude of the second characteristic frequency window and using it as the oil film vortex frequency amplitude; When the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued, and an analysis is performed to determine whether a false alarm occurs. If a false alarm occurs, the alarm threshold is raised; otherwise, an analysis is performed to determine whether a missed alarm occurs. If a missed alarm occurs, the alarm threshold is lowered, including: When the ratio of the oil film vortex frequency to the rotation frequency during the operation of the unit is greater than the alarm threshold, an alarm is automatically issued. When the number of automatic alarms within a fixed time is greater than the preset number threshold and the unit has not failed, it is considered that a false alarm has occurred and the alarm threshold is raised; When the ratio of the oil film turbulence frequency to the rotational frequency during the operation of the unit is not greater than the alarm threshold, when a fault occurs in the unit, it is considered that a missed alarm occurs and the alarm threshold is lowered.

4. The adaptive oil film vortex fault monitoring device according to claim 3, characterized in that: The step of performing Hilbert transform on the vibration signal, extracting the envelope of the vibration signal, and generating an envelope spectrum comprises: pass , perform Hilbert transform on the vibration signal; wherein x(t) is the vibration signal, * is the convolution, is the Hilbert transform of the vibration signal; pass Generate an analytical signal of the vibration signal; wherein z(t) is the analytical signal, ; Performing modulus calculation on the analytical signal to obtain the envelope of the vibration signal; Performing Fourier transform on the envelope to generate an envelope spectrum.

5. An adaptive oil film vortex fault monitoring device, characterized in that: It comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, an adaptive oil film turbulence fault monitoring method as described in any one of claims 1 to 2 is implemented.

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