Vibration test and diagnosis of unstable vibration of generator rotor Guo Yujie Lu Bing Yuan Liping Henan Electric Power Test Institute Zhengzhou, 450052 Sexual entrance hall failure mechanism and related factors Aberdeen Khan åž å“应 å“应 å“应 å“应 å“应 å“应 å“应 å“应 å“应 å“应 å“应 å“应 å“应 å“应 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 254 The generator rotor adopts air cooling mode, the generator and the exciter rotor adopt the rotor support knot, the No. 1 bearing is seated on the front panel; the No. 2 bearing No. 3 falls in the same bearing and the vertical connection and the exhaust cylinder are connected to the rest. The bearing is a floor-standing bearing; the 5å…® bearing is connected by 5 plates of the exciter frame, and the shaft support is intended. 1 In 1998, after the machine was first started and the mesh was loaded, the horizontal vibration of the No. 4 bearing increased with the load and time. The phenomenon of excessive vibration occurs when the load is extended. The load is 54; the rated load is small, and the maximum value is 02. This vibration failure phenomenon occurs repeatedly in the subsequent start.
1 Vibration test is the cause of vibration, using, 1 knowledge; the multi-dead vibration acquisition system tests the shaft bearing vibration and the shaft vibration of No. 3 bearing No. 4, and obtains the following vibration characteristics.
7 The thermal variable response of the generator bearing has a large vibration variation of the generator bearing after the rated load. It can be regarded as the rated power of the unit of 10 cubits. The reactive load is increased from 1 to 14 cubits. The excitation current increased from 220 to 250. After half an hour, the vibration value of No. 4 bearing No. 4 gradually increased with time. The horizontal vibration value of No. 3 bearing No. 4 increased from 52.741 to 56.8192, respectively. The fundamental frequency vibration phase change was within 10 It shows that the rotor current has a significant influence on the vibration of the generator bearing. There is a time lag phenomenon. The vibration of the speed reduction process is more than that of the soft unit with the rated load vibration when the fast stop is compared with the cold start vibration value. The state 6 dynamic vibration value has an increase in the product. The 5th phantom stop critical speed time bearing vertical change from 35 2 melon to 248159 8th start and stop, 13 å…® 4 bearing shaft vibration baud 3 and 4 test process first 17 cold start When the unit's critical speed is 31, the vertical vibration amplitude of the No. 4 bearing is less than 40. Compared with the 5 times of the cold start, 30, 1 such as the vibration characteristics of the no-load condition, the vibration is mainly the level of the 4th bearing, the 4th bearing is the most The vibration seems to be 50 years. The bearing vibration is similar to the small 10 30. The 3rd cold start vibration station frequency phase is relatively stable. The 4th temperature state starts each bearing. The vibration frequency is generally reduced by 23 times. Under the condition of load and load, the bearing and shaft vibration frequency is in the cluster frequency, and other frequency components are small.
Under the load condition, the vibration amplitude generally increases with the extension of the time, and the horizontal vibration of the bearing changes with the time of the shaft vibration of the No. 4 bearing.
Xi Weige 3 start-up process 3rd and 4th bearing 1 shaft vibration baud 2 vibration fault diagnosis machine hunger vibration property is unstable ordinary forced vibration by detecting the connection stiffness and vibration signal analysis of each bearing, can eliminate the unit after load The problem of poor dynamic stiffness of the bearing; the vibration acceleration characteristic of the cold start of the unit and the vibration characteristic of the empty load of 30001.1 can eliminate the faults such as the excessively large deviation of the wheel connection. The vibration test and vibration characteristics can be considered as the unit. The vibration change is mainly caused by the change of the balance state of the generator rotor after the large load of the grid. The obvious heat change of the generator is caused by the hunger operation. The generator rotor is affected by the household excitation current and generates thermal imbalance, which includes time. Under the same excitation current, the vibration increases with time, and there is a time lag phenomenon, indicating that the generator rotor produces thermal bending or thermal imbalance.
Combined with the structure and vibration characteristics of the generator rotor itself, as the newly installed unit has thermal bending and irregular thermal deformation after the grid-connected load, the thermal resistance between the rotor coil and the trunk can not be ruled out. Difference; the thermal resistance of the axial heat transfer direction of the shaft is not uniform; the rotor coil is partially short-circuited or the inter-turn short circuit; 3 The vibration mechanism analysis is called the temperature difference, causing thermal bending and irregular thermal deformation of the generator rotor, which causes this phenomenon. The main reasons are the above eight factors.
The deflection of the generator rotor due to thermal bending can be approximated by the following formula for the length of the rotor wood portion; the linear expansion coefficient of the steel is about. 5 CTlA;j3i;cl=For the deflection radius of the rotor, the diameter of the rotor body part is calculated. The rotor radial temperature difference of this type of unit is 30001. The heat deflection will be about 24, and measures taken at the site should be checked. It is difficult to produce various factors for the thermal bending of the generator rotor. Therefore, dynamic fault compensation is often used to deal with thermal bending and irregular thermal deformation vibration faults of the generator rotor. That is, the rotor is weighted to compensate part of the vibrational heat variable. The balance weight is about 6 times and 7 times of the rotor heat variable. At the same time, the critical speed and the no-load 30001.1 are considered. The vibration under working conditions should not be too large. After the balance of the balance of the heart ring on both sides of the generator rotor is corrected, the unit is under no-load 3000 1., and the rated load condition, the vibration value of the shaft bearing is less than 30, so that the unit is put into safe operation. 5 The main reason for the vibration of the unit is The anti-motor rotor of the mountain plant is in operation with load 17 production. 1. The hot curve and irregular thermal deformation According to the domestic operating experience and vibration fault diagnosis, the generator rotor produces a more obvious thermal deformation fault.
The characteristics of generator thermal bending and irregular thermal deformation vibration faults are that the fundamental frequency component is small, which is related to the excitation current and time. There is obvious time lag phenomenon on-site mining, and the dynamic balance is solved at the dynamic balance. Irregular heat deformation vibration failure of the kind of room measures, changed, machine. The vibration condition, 1 Shi Weixin. Turbogenerator vibration. Beijing Water and Electric Power Press, 1994 2 Gu Huang. Vibration and balance of steam turbine generator sets. Beijing China Electric Power Press, 1998, the author of the article Guo Yujie male. Born in June. Engineers; mainly from the vibration fault test and diagnosis of the rotating machinery and the test and inspection work of the steam turbine equipment of the power station. Zeng Faxin Yangpingqiao Power Plant 10 Unit Vibration Fault jS Pass
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