The measurement method of wobble degree: The measurement of wobble degree of rotor is carried out in the turbine bearing. First, the measuring point is polished smooth, and the dial gauge frame is fixed on the bearing or cylinder horizontal joint surface. In order to measure the position of the maximum wobble, the circumference should be divided into eight equal parts and numbered counterclockwise with a pen. The measuring rod of the meter is aligned at position 1 and perpendicular to the surface, and the part is properly compressed so that the large needle points to "50". Rotate the steering wheel to move the rotor, align each point in order to measure, and record the value of each measurement point. The maximum sloshing value is the maximum difference between the relative values at both ends of the diameter, and 1/2 of the maximum sloshing degree is the maximum bending value.

The sloshing degree is related to the following factors:

1, the temperature difference between the upper and lower walls of the cylinder;

2, shaft seal steam supply temperature;

3. One side shaft seal is seriously worn;

4. the journal in operation vibration and bearing tungsten gold off; 5, the shaft end parts have friction and vibration;

5. the shaft segment or impeller hub has serious friction on one side;

6. turbine vibration and overhaul process medium. The definition and influencing factors of eccentricity of large shaft of steam turbine: eccentricity measurement has become an essential measurement item in the process of starting or stopping steam turbine. It can measure the magnitude of shaft bending caused by heat or gravity. Eccentricity is the measurement of shaft bending at low speed, which can be caused by the following conditions: the original mechanical bending, the bending caused by temporary temperature rise, and some downward bending under static conditions, sometimes called gravity bending. The eccentric position of the rotor, also known as the radial position of the shaft, is often used to indicate bearing wear and the amount of load applied, such as that caused by misalignment. It is also used to determine the azimuth of the shaft, which can indicate whether the rotor is stable. Eccentricity detection system DYW-P type eccentricity monitoring instrument is a precision measurement and control instrument. With alarm and shutdown control signal output, with current output universal interface, can be connected with computers and other equipment. The monitor adopts 160×80(mm) general chassis, LED digital display,PVC color mask and light touch key, beautiful appearance, novel style, reasonable structure, simple installation, stable performance, reliable quality and accurate measurement.

There are several reasons for the turbine eccentricity that often occurs on site:

1, the measurement device itself has a problem, resulting in a large swing of the measured value, which can not be read. It is suggested that the maintenance and inspection of the turbine should be handled, and the mechanical measurement and thermal measurement should be proofread;

2, the original opening of the turbine to the wheel installation is unqualified, more than 80um, resulting in a large eccentricity and the original value of 20um or more. This phenomenon is generally not easy to adjust, to adjust the wheel;

3. Eccentricity increases during operation, and there may be some factors such as static and static friction, oil film oscillation, steam temperature drop or water shock, steam flow excitation, electromagnetic interference, insufficient bearing oil film stiffness, turbine rotor parts falling off or loose;

4. Steam turbine rotor appears hot bending or cracks;

5. the unit starts the process of cylinder temperature difference, especially the upper and lower cylinder temperature difference and flange inside, outside the wall temperature difference exceeds the eccentric increase;

6. the unit cold start warm machine is not good, cylinder expansion blocked, will cause the eccentricity increase;

7. the unit hot start steam intake parameter selection does not match, will cause the unit eccentricity increase;

8. the unit operation bearing tight force is insufficient or oil deformation teeth;

9. shaft seal steam supply shortage will also lead to greater eccentricity;

10. Uneven material of turbine rotor, insufficient stress release, thermal stress in operation. In short, the eccentricity reflects the misalignment of the rotor in the unit turning state, and the shaft vibration level is reflected after the unit runs into the oil film stability period.