Irregular fluctuations in turbine bearing vibration
Thread Content
Recently, the vibration of the turbine bearings in the hydrogenation unit has shown irregular fluctuations. It is a back-pressure type turbine from Hangzhou Steam; after checking, the temperature and pressure of the power steam and back-pressure steam were found to be normal, the compressor was not experiencing surging, and there were no changes in the process medium. Reducing the rotational speed did not result in any significant changes in the fluctuations; the fluctuations remained irregular. Please attach the spectral analysis from the last fluctuation period; I hope experts can help analyze it.
It’s difficult to explain this phenomenon clearly; one can only wait and see the trend line as it continues to develop. . . . . Just like the observation period required after a patient is admitted to the hospital. At this time, it is neither possible to conduct a disassembly inspection nor to shut down the machine for other improvement work. Just wait. . . . Everyone wants to understand the reasons behind something as soon as possible, but one also has to consider its complexity.
Has something gone inside the shaft? This thing isn’t large, and it can move around randomly as it rotates on its axis, resulting in irregular vibrations.
This phenomenon also occurs in our condensing steam turbines; the vibration levels fluctuate irregularly, and it also affects the compressors. The reason is still unknown at the moment.
Both the vibration and phase have changed. A similar situation occurred with one of our units as well; it was later found that high temperatures at the oil baffle caused the lubricating oil to carbonize and form scale, leading to friction and irregular vibration patterns. Just keep blowing in some nitrogen.
Our Hangzhou Motor Company’s turbines have also experienced this problem: irregular fluctuations in vibration levels, with no obvious abnormalities such as visible vibration at the site. It was later found that a large amount of insulation material mixed with lubricating oil had accumulated in the oil area at the turbine head, causing intermittent friction against the shaft. By moving the insulation material back slightly or separating it from that area, and especially by ensuring that the insulation material is not placed too close to the oil area at the turbine head during installation of new turbines, such problems can be avoided. During operation, it is important to keep the negative pressure in the oil tank at a moderate level; additionally, introducing nitrogen flow to clean that area has helped to prevent similar issues from occurring again.
Hello, how do I add nitrogen? Thank you
A stream of compressed air can be directly connected from the air compressor
Blowing nitrogen at the bearing is sufficient! !