Early warning method for vibration fault of rotating machine

Abstract

The invention provides a rotary machine vibration fault early warning method comprising the following steps: recording a vibration pass frequency value of a rotary machine, converting vibration original data collected by a vibration sensor into a series of frequency multiplication components, and recording a vibration vector of each frequency multiplication component, the vibration vector comprising a vibration amplitude and a phase; calculating the vibration variation of the vibration vector of each frequency multiplication component at the current moment and before a period of time, and recording the vibration variation as a vibration slow variation value; calculating the vibration variable quantity of the vibration vector of each frequency multiplication component at the current moment and before one second, and recording the vibration variable quantity as a vibration abrupt change value; and calculating difference values between the vibration slow change value, the vibration sudden change value and the vibration pass frequency value of each vibration vector and the corresponding upper limit, and when any difference value is less than or equal to 0, giving an alarm. Vector early warning is adopted, the directivity of vibration, the change characteristics of vibration and the damage degree of the fault corresponding to each fault frequency component to the unit are comprehensively considered, and the damage level of the current vibration fault to the unit and the vibration change of equipment can be truly reflected.

Description

Technical Field

[0001] The present invention belongs to the technical field of rotating machinery fault detection, and in particular relates to a rotating machinery vibration fault early warning method. Background Art

[0002] Vibration protection is a crucial component of rotating equipment safety. Vibration values ​​exceeding alarm thresholds or tripping thresholds often indicate a certain degree of vibration failure within the equipment, requiring enhanced monitoring, timely treatment, or immediate shutdown. Therefore, determining vibration alarm values ​​is crucial, ensuring they accurately reflect the extent of the fault within the equipment. A value that is too low can trigger an early alarm and lead to excessive handling measures, resulting in significant downtime and maintenance costs. A value that is too high can cause internal vibration failures to develop uncontrollably, posing a significant safety risk.

[0003] Existing vibration protection primarily relies on amplitude alarms, using a set vibration amplitude across the entire frequency range as the alarm threshold. For example, for shaft vibration, 90 μm is used as the alarm threshold. This alarm setting method offers the advantages of simplicity, convenience, and high operability. However, it also has significant disadvantages. First, vibration is a vector and directional. Many faults often develop through changes in angle while maintaining little amplitude. Using amplitude alarms alone cannot truly reflect the development of internal equipment faults, leading to missed faults. Second, from the perspective of vibration fault mechanisms and equipment safety, high vibration levels are often less harmful to the unit than sudden or rapid vibration increases. High but stable vibration levels generally allow the unit to operate safely until the next maintenance appointment without intervention. However, rapid vibration increases and sudden diagnostic changes often indicate serious internal faults, such as friction, loose couplings, rotor cracks, loose rotating components, bearing instability, steam flow excitation, bearing failure, or support cracks. These faults often develop rapidly and can have serious consequences.

[0004] The prior art proposes to use the ratio of the climbing amplitude to the alarm value to determine the alarm value. This method has certain improvements and takes into account the vibration climbing amplitude. However, the same problem exists in that it does not consider the directionality of the vibration or the rate of vibration climbing. It only considers the climbing amplitude and cannot provide a more effective early warning for malignant faults such as rotor cracks, loose couplings, loose rotating parts, bearing instability, steam flow excitation, bearing failure, and support cracks. Because the development of these faults is closely related to the vibration frequency, vibration direction, and vibration climbing speed, using only the vibration climbing amplitude for early warning will only cause a serious lag in the early warning, bringing greater risks. Therefore, the present invention provides a rotating machinery vibration fault early warning method that considers the directionality of the guided vibration to solve the above problems. Summary of the Invention

[0005] The present application provides a rotating machinery vibration fault early warning method, which optimizes the existing vibration early warning value setting method, solves the problem that the traditional early warning value does not consider the directionality of vibration, the rate of vibration climbing, and even the vibration climbing amplitude, so that the early warning value can more truly reflect the development degree of internal faults of the equipment and the damage degree of different fault types to the equipment.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The present application provides a rotating machinery vibration fault early warning method, which optimizes the existing vibration early warning value setting method, solves the problem that the traditional early warning value does not consider the directionality of vibration, the rate of vibration climbing, and even the vibration climbing amplitude, so that the early warning value can more truly reflect the development degree of internal faults of the equipment and the damage degree of different fault types to the equipment.

[0008] S1, record the vibration passband value of the rotating machinery, and convert the vibration original data collected by the vibration sensor into a series of frequency multiplication components, record the vibration vector of each frequency multiplication component, and the vibration vector includes the vibration amplitude and the phase (angle);

[0009] S2, calculate the vibration change amount of each frequency multiplication component vibration vector at the current time and a period of time ago, and record it as the vibration slowly changing value;

[0010] S3, calculate the vibration change amount of each frequency multiplication component vibration vector at the current time and one second ago, and record it as the vibration slowly changing value;

[0011] S4, calculate the difference between the vibration slowly changing value, the vibration sudden change value, the vibration passband value of each vibration vector and the corresponding upper limit, and when any one of the difference values is less than or equal to 0, an alarm is given.

[0012] Further, in the step S1, the vibration passband value and the vibration vector are recorded and stored by seconds, and a total of h length of time data is stored, and the value of h mainly reflects the length of time of vibration slowly changing, which can be 10-30 minutes.

[0013] Further, in the step S1, the vibration amplitude of the frequency multiplication component is X n , and the angle of the frequency multiplication component is θ n ; wherein n is the multiple value of the frequency multiplication component, and the size of n mainly depends on the specific equipment type, and is generally not more than 5, and n can be a non-integer or an integer.

[0014] Further, the rotating machinery is a steam turbine generator, and the vibration vectors of the 1 frequency multiplication component, the 2 frequency multiplication component and the 0.5 frequency multiplication component are recorded.

[0015] Further, the rotating machinery is a rotating device supported by a rolling bearing, and the vibration vectors of the 1 frequency multiplication component, the 2 frequency multiplication component, the frequency multiplication component corresponding to the rolling bearing inner ring fault frequency, the frequency multiplication component corresponding to the rolling bearing outer ring fault frequency, the frequency multiplication component corresponding to the rolling bearing ball fault frequency and the frequency multiplication component corresponding to the rolling bearing cage fault frequency are recorded.

[0016] Furthermore, the rotating machine is a gearbox device, and the vibration vectors of the 1st harmonic component, the 2nd harmonic component, and the harmonic component corresponding to the gear meshing frequency are recorded.

[0017] Furthermore, in step S2, the current time is set as T0, and the time a period of time (h time length) ago is set as T h , then the nth frequency component is at time T0 and T h The vibration slow change value at the moment is ΔL n ; Among them, A is the vibration amplitude of the nth frequency component at time T0, B is T h The vibration amplitude of the nth frequency component at the moment, is the angle of the nth frequency multiplication component at time T0, T h The angle of the nth frequency component at the moment.

[0018] Furthermore, in step S3, assuming that the current time is T0 and the time one second ago is T1, the vibration mutation value of the nth frequency component at time T0 and time T1 is ΔS n ; Among them, A is the vibration amplitude of the nth frequency multiplication component at time T0, C is the vibration amplitude of the nth frequency multiplication component at time T1, is the angle of the nth frequency multiplication component at time T0, is the angle of the nth frequency multiplication component at time T1.

[0019] Furthermore, the step S4 is specifically as follows:

[0020] S4.1. Create a first array based on the obtained vibration slow change value, vibration sudden change value, and vibration full frequency value at the current moment, and use it as the vibration alarm value. First array: A Larm =[P0ΔL1ΔL2ΔL3......ΔL n ΔS1ΔS2ΔS3......ΔS n ]; where ΔL n is the vibration slow-changing value of the nth frequency component at the current moment and a period of time ago, ΔS n is the vibration mutation value of the nth frequency component at the current moment and one second ago, and P0 is the vibration full-frequency value at the current moment;

[0021] S4.2. Create a second array based on the upper limits of the vibration slow-change value, vibration sudden-change value, and vibration full-band value:

[0022] AL0=[p0Δl1Δl2Δl3……Δl n Δs1Δs2Δs3......Δs n]; wherein, Δl n is an upper limit value of the vibration slowly changing value, Δs n is an upper limit value of the vibration suddenly changing value, and p0 is an upper limit value of the vibration pass frequency value.

[0023] S4.3, calculating the difference between each value of the first array and each value corresponding to the second array to create a third array:

[0024] Δ AL = A Larm - A L0 = [ΔP ΔAL1 ΔAL2 ΔAL3... ΔAL n ΔAS1 ΔAS2 ΔAS3... ΔAS n ]; wherein, ΔP = p0 - P0,

[0025] ΔAL n = Δl n - ΔL n , and ΔAS n = Δs n - ΔS n ; when any value in the third array is less than or equal to 0, an alarm is given.

[0026] Further, when the rotating machine is a steam turbine generator, the alarm value can be set as A Larm = [P0 ΔL1 ΔL2 ΔS1 ΔS2 ΔS 0.5 ], and the limit value is A L0 = [90 50 30 20 10 50], the slowly changing time h is set as 20 minutes, and then Δ AL = [90 - P0 50 - ΔL1 30 - ΔL2 20 - ΔS1 10 - ΔS2 50 - ΔS 0.5 ]. When any value in the ΔAL array is less than or equal to 0, an alarm is given, i.e. the current vibration amplitude exceeds 90 um, or the amplitude change of the 1st frequency component within 20 minutes exceeds 50 um, or the amplitude change of the 2nd frequency component exceeds 30 um, or the amplitude change of the 1st frequency component within 1 second exceeds 20 um, or the amplitude change of the 2nd frequency component exceeds 10 um, or the amplitude change of the 0.5th frequency component exceeds 50 um, i.e. a pre-alarm is given.

[0027] The present application has the following advantages:

[0028] Before the present application is adopted, the vibration early warning mainly adopts the general frequency value early warning, without considering that the vibration is a vector, so when the broken blade, rub-impact and other faults occur, the amplitude may not change greatly but the vibration direction may be completely reversed, the real vibration of the shaft system changes greatly, at this time the traditional early warning method will not early warn the fault, and there is a false negative; secondly, the size, change amplitude and change rate of each frequency component are not considered for different types of faults, and the damage degree of the equipment is different, when rub-impact, rotor crack, instability and other faults occur, the general frequency amplitude early warning is still adopted, which will make the alarm lag behind the development of the fault, and the fault develops to the later stage, causing uncontrollable loss.

[0029] The vibration early warning method of the present application adopts vector early warning, comprehensively considers the directionality of vibration, the change characteristics of vibration and the damage degree of the corresponding fault of each fault frequency component to the unit, can more truly reflect the damage level of the current vibration fault to the unit, and can more truly reflect the real vibration change of the equipment.

[0030] The present application considers different frequency components, different change characteristics (slow change, sudden change) representing different fault types, so that different early warning limit values can be set according to the different damage degrees of different fault types to the equipment, so that the early warning value setting is more reasonable.

[0031] The method of the present application has strong applicability and can be applied to different types of equipment, such as sliding bearing supported equipment, rolling bearing supported equipment and gear box. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a flow chart of the vibration fault early warning method of the rotating machinery of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely in combination with the embodiments of the present application and the drawings. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0034] Embodiment 1

[0035] The present embodiment provides a steam turbine generator unit vibration alarm method, specifically:

[0036] An early warning is issued for the X-axis vibration value of the #1 watt of a steam turbine generator set. Based on the fault frequency characteristics of the steam turbine generator set, the vibration frequency value is converted into the original vibration data collected by the vibration sensor into frequency components. The vibration amplitude and phase of the 1st frequency component, 2nd frequency component, and 0.5 frequency component are recorded and stored on a second-by-second basis. A total of 20 minutes of data is stored, and an early warning is issued based on the absolute value and long-term and short-term changes.

[0037] (1) The parameters at the current time (07:51:49) are recorded as follows:

[0038] Vibration frequency value: 45um;

[0039] 1st harmonic component vibration amplitude and angle: 21um, 223°;

[0040] 2nd harmonic component: 10um, 94°;

[0041] 0.5 octave frequency component: 0um, 0°.

[0042] (2) 20 minutes ago (07:31:49), the parameters were recorded as follows:

[0043] 1st harmonic component vibration amplitude and angle: 50um, 128°;

[0044] 2nd harmonic component: 8um, 81°;

[0045] 0.5 octave frequency component: 1um, 304°.

[0046] (3) One second ago (07:51:48), the transient amplitudes of each parameter are recorded as follows:

[0047] 1st harmonic component vibration amplitude and angle: 21um, 219°;

[0048] 2nd harmonic component: 10um, 92°;

[0049] 0.5 octave frequency component: 0um, 27°.

[0050] (4) Calculate the vibration slow change value and vibration sudden change value:

[0051] The vibration slow change value of each frequency component: ΔL1=56, ΔL2=3, ΔL 0.5 =1;

[0052] The vibration mutation values ​​of each harmonic component are: ΔS1=1, ΔS2=0, ΔS3=0.

[0053] (5) Early warning strategy:

[0054] Create the first array A based on the obtained vibration slow change value, vibration sudden change value, and vibration frequency value at the current momentLarm =[P0ΔL1ΔL2ΔS1ΔS2ΔS 0.5 ], is the alarm combination. Specifically, the first array AL arm =[45 56 3 1 0 0];

[0055] According to the equipment type and experience, the upper limit of each vibration slow change value, vibration sudden change value, and vibration full frequency value is determined to create a second array. The second array AL0 = [90 50 30 20 10 50];

[0056] Calculate the difference between each value in the first array and the corresponding value in the second array to create a third array. AL =A Larm -A L0 =[45 -6 27 19 10 50], that is, within 20 minutes, the 1-octave frequency component exceeds 50, and an early warning should be issued.

[0057] Traditional alarm methods only consider whether the vibration through-band value P0 is above the alarm threshold of 90. If it is not, no warning is issued. However, according to the results of the present invention, if the stored value is less than or equal to 0, a warning should be issued. In reality, the 1-fold frequency vector value varies significantly, indicating a dynamic-static friction fault has occurred in the unit.

[0058] This invention overcomes the drawback of traditional vibration early warning methods that only use general frequency values ​​for early warning without considering the vibration vector. Instead, it comprehensively considers the directionality of vibration, the vibration variation characteristics, and the degree of harm to the unit caused by the fault corresponding to each fault frequency component. This method can more accurately reflect the level of harm caused by the current vibration fault to the unit and better reflect the actual vibration changes of the equipment. Furthermore, this invention considers the fault types represented by different frequency components and different variation characteristics (slow change, sudden change), thereby enabling different early warning limits to be set according to the different degrees of harm caused by different fault types to the equipment, making the early warning value setting more reasonable.

[0059] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A rotating machinery vibration fault early warning method, characterized in that: include: S1. Record the vibration frequency value of the rotating machinery, convert the original vibration data collected by the vibration sensor into a series of frequency multiplication components, and record the vibration vector of each frequency multiplication component. The vibration vector includes the vibration amplitude and phase; S2. Calculate the vibration change of each frequency-multiplier vibration vector between the current moment and a period of time ago, and record it as the vibration slow-changing value; S3. Calculate the vibration change of each frequency-multiplier vibration vector between the current moment and one second ago, and record it as the vibration mutation value; S4. Calculate the difference between the vibration slow change value, vibration sudden change value, vibration full-frequency value of each vibration vector and the corresponding upper limit. When any of the differences is less than or equal to 0, an alarm is issued.

2. The rotating machinery vibration fault early warning method according to claim 1, characterized in that: In step S1, the vibration frequency value and the vibration vector are recorded and stored per second, and data of a time length of h is stored in total, where h is 10-30 minutes.

3. The rotating machinery vibration fault early warning method according to claim 1, characterized in that: In step S1, the vibration amplitude of the frequency multiplication component is X n , the angle of the double frequency component is θ n ; Wherein, n is the multiple value of the frequency multiplication component, and n≤5.

4. The rotating machinery vibration fault early warning method according to claim 3, characterized in that: The rotating machine is a steam turbine generator, and the vibration vectors of the 1st multiplication frequency component, the 2nd multiplication frequency component and the 0.5th multiplication frequency component are recorded.

5. The rotating machinery vibration fault early warning method according to claim 3, characterized in that: The rotating machinery is a rotating device supported by a rolling bearing, and records the vibration vectors of the 1st frequency component, the 2nd frequency component, the frequency component corresponding to the rolling bearing inner ring fault frequency, the frequency component corresponding to the rolling bearing outer ring fault frequency, the frequency component corresponding to the rolling bearing ball fault frequency, and the frequency component corresponding to the rolling bearing retainer fault frequency.

6. The rotating machinery vibration fault early warning method according to claim 3, characterized in that: The rotating machine is a gearbox device, and the vibration vectors of the 1st harmonic component, the 2nd harmonic component, and the harmonic component corresponding to the gear meshing frequency are recorded.

7. The rotating machinery vibration fault early warning method according to claim 1, characterized in that: In step S2, the vibration slow change value of the nth frequency component at the current moment and a period of time ago is ΔL n ; described Among them, A is the vibration amplitude of the nth frequency multiplication component at the current moment, and B is the vibration amplitude of the nth frequency multiplication component at the moment h time length ago. is the angle of the nth frequency component at the current moment, It is the angle of the nth frequency component at a time length h before.

8. The rotating machinery vibration fault early warning method according to claim 7, characterized in that: In step S3, the vibration mutation value of the nth frequency component at the current moment and one second ago is ΔS n ; described Among them, A is the vibration amplitude of the nth frequency multiplication component at the current moment, and C is the vibration amplitude of the nth frequency multiplication component one second ago. is the angle of the nth frequency component at the current moment, is the angle of the nth frequency component one second ago.

9. The rotating machinery vibration fault early warning method according to claim 8, characterized in that: The step S4 is specifically as follows: Create the first array based on the obtained vibration slow-changing value, vibration sudden-changing value, and vibration full-frequency value at the current moment: AL arm =[P0ΔL1ΔL2ΔL3......ΔL n ΔS1ΔS2ΔS3......ΔS n ]; where ΔL n is the vibration slow-changing value of the nth frequency component at the current moment and a period of time ago, ΔS n is the vibration mutation value of the nth frequency component at the current moment and one second ago, and P0 is the vibration full-frequency value at the current moment; Create a second array based on the upper limits of each vibration slow change value, vibration sudden change value, and vibration full frequency value: AL0=[p0Δl1Δl2Δl3……Δl n Δs1Δs2Δs3......Δs n ]; where Δln is the upper limit of the vibration ramp value, Δs n is the upper limit of the vibration mutation value, and p0 is the upper limit of the vibration through-band value; Compute the difference between each value in the first array and the corresponding value in the second array to create a third array: D AL =A Larm -A L0 =[ΔPΔAL1ΔAL2ΔAL3......ΔAL n ΔAS1ΔAS2ΔAS3......ΔAS n ]; where, ΔP = p0 - P0, ΔAL n = Δl n - ΔL n , ΔAS n = Δs n - ΔS n ; When any value in the third array is less than or equal to 0, an alarm is issued.

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