A method for quickly identifying contact friction and rotating parts flying off faults

Abstract

The present invention belongs to the field of power machinery engineering and discloses a method for rapidly identifying contact friction and rotating component flyaway faults. The method comprises the following steps: obtaining relative shaft vibration data from each measuring point of a steam turbine generator set by measurement or query, and rapidly identifying measuring points where significant vibration fluctuations occur; obtaining relative shaft vibration data from measuring points where significant vibration fluctuations occur, and performing necessary spectral analysis on the data; determining, based on the vibration data, whether the vibration phenomenon meets the basic characteristics of contact friction and rotating component flyaway faults; and identifying the unit's vibration fault in accordance with the vibration characteristics of contact friction and rotating component flyaway faults. The present invention can rapidly and accurately identify whether a unit has experienced a contact friction fault or a rotating component flyaway fault, providing effective recommended measures for actual production.

Description

Technical Field

[0001] The invention belongs to the field of power machinery engineering and relates to a method for quickly identifying contact friction and rotating component flying-off faults. Background Art

[0002] Vibration is directly related to the safe and stable operation of steam turbine generator sets. Many faults in steam turbine generator sets can cause abnormal vibration. Different faults have distinct vibration characteristics, though these differences can be subtle. Fault diagnosis involves determining the cause of vibration based on these characteristics and related information. The more accurate the fault diagnosis, the more precise and targeted the basis for subsequent maintenance and adjustment of the steam turbine generator set.

[0003] Thermal power units are actively undergoing transformation and upgrading, with progress being made in a coordinated effort to address energy conservation and consumption reduction, heat supply improvements, and flexibility improvements to meet the demands of energy conservation and consumption reduction and the integration of renewable energy. The various energy-saving improvements and flexible operating modes implemented by thermal power units, such as rapid start-stop and deep peak load regulation, have resulted in a continuous decrease in the dynamic and static clearances of steam turbine equipment. This has also deviated from the original design operating conditions, leading to an increase in the frequency of contact friction and vibration failures caused by the separation of rotating components, seriously impacting the safety and reliability of thermal power units.

[0004] Failure to accurately and quickly identify contact friction and rotating part flyaway faults can lead to improper operating measures, risking a unit trip, and even preventing the provision of guidance for subsequent unit maintenance and adjustments. However, the vibrations caused by contact friction and rotating part flyaway faults share similar characteristics, making identification challenging. Therefore, the ability to quickly and accurately identify these faults is crucial and urgent. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a method for quickly identifying contact friction and rotating parts flying off faults. The present invention aims to quickly and accurately identify whether the unit has a contact friction fault or a rotating parts flying off fault, and provide effective recommended measures for actual production.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for quickly identifying contact friction and rotating component fly-off faults comprises the following steps:

[0008] During unit operation, if the first measuring point of the bearing experiences significant vibration fluctuations, and if the vibration of the second measuring point of the bearing changes synchronously with the vibration of the first measuring point, then determine whether the fundamental frequency component is dominant before and after the relative shaft vibration changes. Otherwise, it indicates that the unit is not currently experiencing contact friction or rotating parts flying off. The second measuring point is the relative shaft vibration measurement point of the first measuring point.

[0009] If the fundamental frequency component is dominant before and after the relative shaft vibration changes, the duration of the relative shaft vibration change process at the first measuring point is obtained. If the fundamental frequency component is not dominant before and after the relative shaft vibration changes, it indicates that the unit is not currently experiencing contact friction or rotating parts flying off.

[0010] If the duration of the relative shaft vibration change at the first measuring point is no longer than the preset time, and the unit load remains the same and the monitoring section pressure of the unit changes, it indicates that a rotating component has fallen off the unit, and the location of the component falling off is within the area where the monitoring section pressure has changed.

[0011] If the duration of the relative shaft vibration change process at the first measuring point is greater than the preset time, the amplitude of the shaft vibration change and the unit trip value are used to determine whether contact friction has occurred in the unit.

[0012] Preferably, when the unit is running, the through-frequency and fundamental frequency vibration trend curves are obtained within a period of time before and after the vibration fluctuation of the first measuring point, and data analysis is performed on the through-frequency and fundamental frequency vibration trend curves. It is determined whether obvious vibration fluctuation occurs at the first measuring point based on the analysis results.

[0013] Preferably, when performing data analysis on the through-frequency and fundamental frequency vibration trend curves, the time T at which the vibration fluctuation of the first measuring point starts is obtained on the through-frequency and fundamental frequency vibration trend curves. 01 And the corresponding vibration V 01 , obtain the vibration value V after the first measuring point is moved on the general frequency and fundamental frequency vibration trend curve 11 and time T 11 , set the first measuring point to meet the following conditions:

[0014] ≥30%

[0015] Get the second measuring point at T 01 Vibration of the moment V 02 and T 11 Vibration of the moment V 12 , if the following conditions are met:

[0016] ≥20%

[0017] It is determined that the vibration of the second measuring point changes synchronously with the vibration of the first measuring point; otherwise, it indicates that no contact friction or flying of rotating parts occurs in the unit.

[0018] Preferably, when judging whether the relative shaft vibration before and after the change is dominated by the fundamental frequency component, the relative shaft vibration data of the first measuring point is subjected to spectrum analysis to obtain the relative shaft vibration data of the first measuring point at T 01 The fundamental frequency vibration V 01bf and T 11 The fundamental frequency vibration V at time 11bf ;

[0019] If the following conditions are met:

[0020] ≥70% and ≥70%

[0021] It is judged that the fundamental frequency component is dominant before and after the relative shaft vibration changes, otherwise it indicates that the fundamental frequency component is not dominant before and after the relative shaft vibration changes.

[0022] Preferably, the frequency of the fundamental frequency component is 50 Hz.

[0023] Preferably, the preset duration is set to 1 minute.

[0024] Preferably, if the duration of the relative shaft vibration change process at the first measuring point is no longer than a preset time, and the unit load change is no more than 3MW, it is considered that the unit loads are the same.

[0025] Preferably, the process of determining whether contact friction currently occurs in the unit by using the amplitude of the shaft vibration change and the trip value of the unit includes:

[0026] If the amplitude of the shaft vibration after the change is less than the over-trip value, keep the current operating parameters of the unit stable and start the unit's top shaft oil pump. If the relative shaft vibration of the first measuring point drops to the value before the vibration fluctuation, it indicates that the unit is currently experiencing contact friction; otherwise, the contact friction fault is eliminated;

[0027] If the amplitude of the shaft vibration change is above the trip value and has caused the unit to shut down, use a stethoscope to listen to the sound on site when the speed drops to 500r / min. If an abnormal sound is heard, it indicates that contact friction has occurred in the unit; otherwise, the contact friction fault has been eliminated.

[0028] Preferably, the trip value of the unit is 240 μm;

[0029] When using a stethoscope to listen on site, listen every time the speed drops by 100r / min until the unit is started. If an abnormal sound is heard, it indicates that contact friction has occurred in the unit; otherwise, the contact friction fault has been eliminated.

[0030] Preferably, the angle between the corresponding radii of the first measuring point and the second measuring point distributed on the bearing is 90°.

[0031] The present invention has the following beneficial effects:

[0032] The method of the present invention triggers a vibration fault identification process when the vibration change at a certain bearing of the unit exceeds a given limit; the fault analysis and identification process includes all relative shaft vibration measurement points at the same bearing in the analysis range, fully utilizes the long-term change trend characteristics of the vibration and the spectrum characteristics during the vibration change process, and combines a large number of practical case experiences to provide quantitative differentiation indicators for contact friction and rotating parts flying off, and uses the continuity characteristics after the fault occurs to further verify the fault type; the method of the present invention has clear logic, simple steps, and the data used is easy to obtain, so it is highly operational and timely. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the installation position of the relative axis vibration sensor in Example 1 of the present invention.

[0034] Figure 2 This is a schematic diagram of the installation position of the relative axis vibration sensor in Example 2 of the present invention.

[0035] Figure 3 A simplified diagram of the shafting structure of a steam turbine generator set provided in an embodiment of the present invention.

[0036] Figure 4 Trend curve of 1X relative shaft vibration through-frequency and fundamental frequency in the embodiment of the present invention.

[0037] Figure 5 Trend curve of the 1Y relative axis vibration through-frequency and fundamental frequency in the embodiment of the present invention.

[0038] Figure 6 1X relative axis vibration waveform spectrum diagram at time T01 when the vibration change starts in an embodiment of the present invention.

[0039] Figure 7 1X relative axis vibration waveform spectrum diagram at time T11 after vibration change in an embodiment of the present invention.

[0040] Figure 8 Trend curves of the 1X relative shaft vibration through-frequency and fundamental frequency after starting the top shaft oil pump in the embodiment of the present invention.

[0041] Figure 9 A simplified diagram of the shafting structure of a steam turbine generator set in an embodiment of the present invention.

[0042] Figure 10 3Y relative axis vibration frequency trend curve in the embodiment of the present invention.

[0043] Figure 11 Trend curve of the fundamental frequency of 3Y relative axis vibration in an embodiment of the present invention.

[0044] Figure 12 3X relative shaft vibration frequency trend curve in the embodiment of the present invention.

[0045] Figure 13 3X relative axis vibration fundamental frequency trend diagram in an embodiment of the present invention.

[0046] Figure 14 3Y relative axis vibration waveform spectrum diagram at time T01 when the vibration change starts in an embodiment of the present invention.

[0047] Figure 15 Spectrum diagram of the 3Y relative axis vibration waveform at time T11 after the vibration change in the embodiment of the present invention.

[0048] In the figure, 1-bearing. DETAILED DESCRIPTION

[0049] According to the technical solution of the present invention, those skilled in the art may propose various interchangeable structures and implementations without changing the essential spirit of the present invention. Therefore, the following specific embodiments and drawings are merely illustrative of the technical solution of the present invention and should not be regarded as the entire invention or as limiting its technical solution.

[0050] The method for quickly identifying contact friction and rotating component fly-off faults of the present invention comprises the following steps:

[0051] S1, first find the measuring point where the relative shaft vibration of a bearing on the unit (such as a steam turbine generator unit or a thermal power unit) has obvious fluctuations, and record this measuring point as measuring point M1, and then record another relative shaft vibration measuring point of the bearing as measuring point M2; specifically, the definitions of measuring points M1 and M2 are as follows: Figure 1 and Figure 2 Steam turbine generator sets generally have two relative shaft vibration sensors installed at a certain bearing at a 90° angle. Find the measuring point where the relative shaft vibration fluctuation is most obvious at a certain bearing and record it as M1. The other relative shaft vibration measuring point at the bearing, that is, the adjacent measuring point, is recorded as M2.

[0052] S2, obtaining the general frequency and fundamental frequency vibration trend curves for a period of time before and after the vibration fluctuation of the measuring point M1, and performing data analysis on the general frequency and fundamental frequency vibration trend curves. If the vibration of the measuring point M2 also changes synchronously when the measuring point M1 has obvious vibration fluctuation, then go to step S3; otherwise, it means that the steam turbine generator set currently has no contact friction or rotating parts flying off. Specifically, the specific operations in this step are as follows:

[0053] S21, first obtain the vibration trend curves of the through-frequency and fundamental frequency before and after the vibration fluctuation of the measuring point M1, perform data analysis, and find the time when the vibration fluctuation of the measuring point M1 starts, which is recorded as T 01 , the corresponding vibration when the vibration fluctuation of measuring point M1 begins is V 01 , find out the vibration value V after the measuring point M1 fluctuates 11 , the time corresponding to the fluctuation of measuring point M1 is recorded as T 11 , set the measuring point M1 to meet the following conditions:

[0054] ≥30%

[0055] S22, find the measuring point M2 at T 01 Vibration of the moment V 02 and in T 11 Vibration of the moment V 12 , if the conditions are met If the value of the vibration of the adjacent measuring point M2 is greater than or equal to 20%, it is considered that the vibration of the adjacent measuring point M2 has also changed synchronously, and the process goes to step S3. Otherwise, it indicates that the steam turbine generator set currently has no contact friction or rotating parts flying off.

[0056] S3, performing spectrum analysis on the relative shaft vibration data of measuring point M1 obtained in step S2, to determine whether the relative shaft vibration is dominated by the fundamental frequency component (50 Hz) before and after the change. Generally speaking, when the ratio of the amplitude of the fundamental frequency component to the amplitude of the passband is greater than 70%, it can be considered that the vibration is dominated by the fundamental frequency, and the process goes to step S4; otherwise, it indicates that the steam turbine generator set is not currently experiencing contact friction or rotating component flying off. Specifically, the specific operations in this step are as follows:

[0057] S31, perform spectrum analysis on the relative axis vibration data of the measuring point M1 obtained in step S2, and obtain T 01 The fundamental frequency vibration V of the measuring point M1 at the moment 01bf and T 11 The fundamental frequency vibration V of the measuring point M1 at the moment 11bf ;

[0058] S32, if the conditions are met ≥70% and If the value is ≥70%, it is considered that the fundamental frequency is dominant before and after the vibration change, and the process goes to step S4; otherwise, it indicates that the steam turbine generator set currently does not have contact friction or rotating parts flying off.

[0059] S4, obtain the duration of the vibration change process of the measuring point M1 relative to the shaft. If the duration is less than 1 minute, go to step S5; if the duration is more than 1 minute, go to step S6. Specifically, in this step, the specific operations are as follows:

[0060] If the condition T is met11 -T 01 ≤1min, there is a high possibility of the rotating parts flying off, go to step S5, if the condition T is met 11 -T 01 >1min, go to step S6.

[0061] S5, the unit load is basically the same, and the pressure of the turbine monitoring section changes, which means that the steam turbine generator set has a rotating component flying off, and the position of the component flying off is near the change in the monitoring section pressure; specifically, in this step, the specific operations are as follows: first confirm that the load change of the unit before and after the vibration fluctuation is no more than 3MW, and then query the pressure value of each monitoring section. If the pressure value of the monitoring section changes, it means that the steam turbine generator set has a rotating component flying off failure.

[0062] S6: This step includes the following two situations:

[0063] ① If the amplitude of the vibration change does not exceed the trip value (i.e. V 11 <240μm), keep the current operating parameters of the unit stable, quickly start the top shaft oil pump, and observe the changes in the relative shaft vibration of measuring point M1. If the relative shaft vibration of measuring point M1 slowly decreases to the value before the vibration fluctuation, it means that contact friction has occurred in the steam turbine generator set; otherwise, the contact friction fault has been eliminated.

[0064] ② If the amplitude of the vibration changes exceeds the trip value (i.e. V 11 If the vibration level is greater than or equal to 240μm, the high vibration protection has been triggered, and the unit has been shut down and coasted (i.e., the unit has been shut down). When the speed drops to 500r / min, immediately use a stethoscope to listen to the sound. If an abnormal sound is heard, contact friction is occurring in the turbine generator set. Otherwise, the contact friction fault has been eliminated. During this operation, listen every 100r / min decrease in speed until the unit is cranked. If an abnormal sound is heard, contact friction is occurring in the turbine generator set.

[0065] The implementation process of the present invention is now described in detail through the following Examples 1 and 2 to illustrate the effectiveness and practicality of the present invention.

[0066] Example 1:

[0067] The steam turbine for the No. 1 steam turbine generator unit at a power plant is a C350-24.2 / 0.4 / 566 / 566 supercritical, single-intermediate-reheat, single-shaft, two-cylinder, dual-exhaust, one-stage regulated extraction, condensing steam turbine manufactured by Shanghai Steam Turbine Works Co., Ltd. It is equipped with a QFSN-350-2 water / hydrogen / hydrogen-cooled generator manufactured by Shanghai Electric Machine Works Co., Ltd. The unit's shafting consists of a high- and medium-pressure rotor (HIP), a low-pressure rotor (LP), a generator rotor (GEN), an exciter brush holder (EXC), and six support bearings. A schematic diagram of the unit's shafting is shown below. Figure 3 shown.

[0068] From September to November 2023, the unit underwent a Class A overhaul, during which the unit's shaft system vibration was fully tested. During operation, abnormal relative shaft vibrations 1X and 1Y at bearing #1 occurred. The vibration fault was immediately diagnosed and identified on-site. The detailed process is as follows:

[0069] (1) The on-site operating personnel reported that the relative shaft vibration of the unit exceeded the alarm value (120μm), triggering the alarm signal. After a quick on-site inspection, it was determined that the measuring point where the relative shaft vibration changed significantly was 1X, and its adjacent measuring point was 1Y. Therefore, measuring point 1X was recorded as M1, and measuring point 1Y was recorded as M2.

[0070] (2) Obtain the general frequency and fundamental frequency trend curves of the relative shaft vibration of the measuring point 1X. Figure 4 The trend curves of the frequency and fundamental frequency of the relative axis vibration of measuring point 1Y are shown in Figure 5 .

[0071] Depend on Figure 4 It can be obtained that the time T when the vibration of measuring point 1X relative to the shaft begins to change is 01 , the corresponding vibration V 01 , the vibration value V after vibration change 11 and its corresponding time T 11 , listed in Table 1.

[0072] Table 1

[0073]

[0074] Depend on Figure 5 Combined with Table 1, we can get the time when vibration changes start: T 01 Vibration value V at measuring point 1Y at the moment 02 , and after vibration changes T 11 Vibration value V at measuring point 1Y at the moment 12 , listed in Table 2.

[0075] Table 2

[0076]

[0077] From Table 1 we can get: = >30%

[0078] From Table 2 we can get: = >30%

[0079] The relative axis vibration changes of measuring point 1X and measuring point 1Y both meet the conditions, and the relative axis vibration change of measuring point 1X is more obvious.

[0080] (3) Perform spectrum analysis on the relative axis vibration data of measuring point 1X, and the waveform spectrum is shown in Figure 6 and Figure 7 .

[0081] Depend on Figure 4 、 Figure 6 and Figure 7 You can get T 01 and T 11 The fundamental frequency vibrations of the relative axis vibration of the measuring point 1X at the moment are V 01bf and V 11bf , listed in Table 3.

[0082] Table 3

[0083]

[0084] From Table 1 and Table 3, we can get: >70%

[0085] From Table 1 and Table 3, we can get: >70%

[0086] It can be concluded that the change in the relative shaft vibration of measuring point 1X is mainly based on the fundamental frequency.

[0087] (4) Based on the previous analysis and calculation, the duration of the relative axis vibration change process of the measuring point 1X is obtained, that is, T 01 and T 11 Time difference:

[0088] T 11 -T 01 8 minutes and 6 seconds

[0089] Since the vibration change process lasts for more than 1 minute, the possibility of contact friction is high.

[0090] (5) The value of the relative shaft vibration at measuring point 1X after the change is 182μm, which is less than the trip protection value (240μm). However, considering that the vibration value is still large, in order to ensure the safety of the equipment, the on-site operator is advised to start the top shaft oil pump immediately. At 16:20:27 on November 10, 2023, the top shaft oil pump was started. The other parameters of the unit remained stable. The vibration operation was observed. At 16:20:02, the 1X relative shaft vibration began to slowly decrease. After a period of time, its value basically dropped to the value before the vibration fluctuation. Figure 8 .

[0091] Through the above diagnostic analysis and identification process, it has been identified that the unit has a contact friction vibration fault. It is recommended to control the unit operating parameters to be stable so that the unit can operate normally.

[0092] Due to the accurate fault identification, unnecessary shutdown of the unit was avoided, and the power plant recovered economic losses.

[0093] Example 2:

[0094] The steam turbine for the No. 1 steam turbine generator unit at a power plant is a N300-16.7 / 537 / 537-8 subcritical, single-intermediate-reheat, two-cylinder, two-exhaust condensing steam turbine manufactured by Dongfang Steam Turbine Works Co., Ltd. It is equipped with a QFSN-300-2-20B water / hydrogen / hydrogen-cooled generator manufactured by Dongfang Electric Machinery Works Co., Ltd. The unit's shafting consists of a high- and medium-pressure rotor (HIP), a low-pressure rotor (LP), a generator rotor (GEN), an exciter brush holder (EXC), and six support bearings. A simplified diagram of the unit's shafting is shown below. Figure 9 shown.

[0095] On April 21, 2023, during normal operation under load, the unit experienced a sudden increase in vibration, seriously impacting its safe operation. Using the TDM data provided by the unit, we immediately conducted remote diagnosis, analysis, and identification of the vibration fault. The specific process is as follows:

[0096] (1) The alarm signal of Unit 1 is triggered, indicating that the relative shaft vibration of the unit exceeds the alarm value (120μm).

[0097] After a quick on-site check by the operation monitoring personnel, it was determined that the measuring point with obvious changes in relative shaft vibration was 3Y, and its adjacent measuring point was 3X. Therefore, measuring point 3Y was recorded as M1, and measuring point 3X was recorded as M2.

[0098] (2) Obtain the general frequency and fundamental frequency trend curves of the relative axis vibration of the measuring point 3Y. Figure 10 and Figure 11 , the trend curve of the frequency and fundamental frequency of the relative shaft vibration of measuring point 3X is shown in Figure 12 and Figure 13 .

[0099] Depend on Figure 10 The time T when the vibration of measuring point 3Y relative to the axis starts to change can be obtained 01 , the corresponding vibration V 01 , the vibration value V after vibration change 11 and its corresponding time T 11 , listed in Table 4.

[0100] Table 4

[0101]

[0102] Depend on Figure 12 Combined with Table 1, we can get the time when vibration changes start: T 01 The relative axis vibration value V at the measuring point 3X at the moment 02 , and after vibration changes T 11 The relative axis vibration value V at the measuring point 3X at the moment 12 , listed in Table 5.

[0103] Table 5

[0104]

[0105] From Table 4 we can get: = >30%

[0106] From Table 5 we can get: = >30%

[0107] The relative axis vibration changes of measuring points 3X and 3Y both meet the conditions, and the relative axis vibration change of measuring point 3Y is more obvious.

[0108] (3) Perform spectrum analysis on the relative axis vibration data of measuring point 3Y, and the waveform spectrum is shown in Figure 14 and Figure 15 .

[0109] Depend on Figure 11 、 Figure 14 and Figure 15 You can get T 01 and T 11 The fundamental frequency vibrations of the relative axis vibration of the measuring point 3Y at the moment are V 01bf and V 11bf , listed in Table 6.

[0110] Table 6

[0111]

[0112] From Table 4 and Table 6, we can get: >70%

[0113] From Table 4 and Table 6, we can get: >70%

[0114] It can be concluded that the change in the relative axis vibration of measuring point 3Y is mainly based on the fundamental frequency.

[0115] (4) Based on the previous analysis and calculation, the duration of the vibration change process of the measuring point 3Y relative to the axis is obtained, that is, T 01 and T 11 Time difference:

[0116] T 11 -T 01 52 seconds

[0117] Since the vibration change process lasts less than 1 minute, the diagnosis shows a high possibility of rotating parts flying off.

[0118] (5) The operating personnel were asked to check the pressure values ​​of each monitoring section and the changes in unit load during the vibration change process. After checking, the unit load was 249MW and 247MW before and after the vibration change, respectively. The load remained basically unchanged, but the fifth stage extraction steam pressure changed by 0.1MPa.

[0119] Through the above diagnostic analysis and identification process, it has been identified that a rotating component has fallen off the unit, and the location of the component falling off is near the fifth stage. It is recommended to strengthen the vibration monitoring operation of the unit and arrange a shutdown inspection as soon as possible to avoid causing other secondary hazards and causing greater losses.

[0120] After a week of monitored operation, the unit was shut down for maintenance with grid approval. Upon opening the low-pressure cylinder for inspection, a broken rotor blade on the fourth reverse stage of the low-pressure rotor was discovered, along with a portion of the shroud that had fallen off. After replacing the blades and shroud, the unit's relative shaft vibration values ​​at all measurement points remained within the excellent range specified by the national standard (GB / T11348.2-2012) after startup.

[0121] The above describes in detail the specific embodiments of the present invention. It should be understood that numerous modifications and variations based on the concepts of the present invention can be made by those skilled in the art without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology should be within the scope of protection of the claims of the present invention.

Claims

1. A method for quickly identifying contact friction and rotating parts flying off faults, characterized in that: The following steps are involved: During unit operation, if the first measuring point of the bearing experiences significant vibration fluctuations, and if the vibration of the second measuring point of the bearing changes synchronously with the vibration of the first measuring point, then determine whether the fundamental frequency component is dominant before and after the relative shaft vibration changes. Otherwise, it indicates that the unit is not currently experiencing contact friction or rotating parts flying off. The second measuring point is the relative shaft vibration measurement point of the first measuring point. If the fundamental frequency component is dominant before and after the relative shaft vibration changes, the duration of the relative shaft vibration change process at the first measuring point is obtained. If the fundamental frequency component is not dominant before and after the relative shaft vibration changes, it indicates that the unit is not currently experiencing contact friction or rotating parts flying off. If the duration of the relative shaft vibration change at the first measuring point is no longer than the preset time, and the unit load remains the same and the monitoring section pressure of the unit changes, it indicates that a rotating component has fallen off the unit, and the location of the component falling off is within the area where the monitoring section pressure has changed. If the duration of the relative shaft vibration change process at the first measuring point is greater than the preset time, the amplitude of the shaft vibration change and the unit trip value are used to determine whether contact friction has occurred in the unit. When the unit is running, obtain the general frequency and fundamental frequency vibration trend curves for a period of time before and after the vibration fluctuation of the first measuring point, perform data analysis on the general frequency and fundamental frequency vibration trend curves, and judge whether obvious vibration fluctuation occurs at the first measuring point based on the analysis results; When analyzing the data of the through-frequency and fundamental frequency vibration trend curves, the time T when the vibration fluctuation of the first measuring point starts is obtained on the through-frequency and fundamental frequency vibration trend curves. 01 And the corresponding vibration V 01 , obtain the vibration value V after the first measuring point is moved on the general frequency and fundamental frequency vibration trend curve 11 and time T 11 , set the first measuring point to meet the following conditions: ≥30% Get the second measuring point at T 01 Vibration of the moment V 02 and T 11 Vibration of the moment V 12 , if the following conditions are met: ≥20% It is judged that the vibration of the second measuring point changes synchronously with the vibration of the first measuring point. Otherwise, it indicates that the unit currently does not have contact friction or rotating parts flying off; When judging whether the relative shaft vibration before and after the change is dominated by the fundamental frequency component, the spectrum analysis of the relative shaft vibration data of the first measuring point is performed to obtain the first measuring point at T 01 The fundamental frequency vibration V 01bf and T 11 The fundamental frequency vibration V at time 11bf ; If the following conditions are met: ≥70% and ≥70% It is judged that the fundamental frequency component is dominant before and after the relative shaft vibration changes, otherwise it indicates that the fundamental frequency component is not dominant before and after the relative shaft vibration changes; The process of determining whether contact friction has occurred in the unit by using the amplitude of the shaft vibration change and the unit trip value includes: If the amplitude of the shaft vibration after the change is less than the over-trip value, keep the current operating parameters of the unit stable and start the unit's top shaft oil pump. If the relative shaft vibration of the first measuring point drops to the value before the vibration fluctuation, it indicates that the unit is currently experiencing contact friction; otherwise, the contact friction fault is eliminated; If the amplitude of the shaft vibration change is above the trip value and has caused the unit to shut down, use a stethoscope to listen to the sound on site when the speed drops to 500r / min. If an abnormal sound is heard, it indicates that contact friction has occurred in the unit; otherwise, the contact friction fault has been eliminated.

2. A method for quickly identifying contact friction and rotating component fly-off faults according to claim 1, characterized in that: The frequency of the fundamental frequency component is 50 Hz.

3. The method for quickly identifying contact friction and rotating component flying-off faults according to claim 1, characterized in that: The preset duration is set to 1 minute.

4. A method for rapidly identifying contact friction and rotating component fly-off faults according to claim 1, characterized in that: If the duration of the relative shaft vibration change process at the first measuring point is no longer than the preset time, and the unit load change is no more than 3MW, the unit load is considered to be the same.

5. The method for quickly identifying contact friction and rotating component flying-off faults according to claim 1, characterized in that: The trip value of the unit is 240μm; When using a stethoscope to listen on site, listen every time the speed drops by 100r / min until the unit is started. If an abnormal sound is heard, it indicates that contact friction has occurred in the unit; otherwise, the contact friction fault has been eliminated.

6. The method for quickly identifying contact friction and rotating component flying-off faults according to claim 1, characterized in that: The angle between the corresponding radii of the first measuring point and the second measuring point on the bearing is 90°.

Images