The temperature of the syngas compressor bearing shells is high, and vibration is present. Please help analyze the possible reasons
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Compressor model D10R5S: Delaiselan, five-stage, two-section design, driven by a turbine. Since January of this year, the temperature of the bearing shells has continued to rise; there were fluctuations in this temperature over time, and the drive-end bearing was replaced once. The vibration is normal at the moment; the oil return temperature is 53 degrees and the oil supply temperature is 40 degrees. I’m not sure what caused the increase in temperature – I seek an explanation.
What are the oil pressure and volume in the branch? Are the lubricant specifications meeting the requirements? Have there been any changes in load or speed? Also, has the probe been checked? Were there any issues with the bearings that were replaced previously? If there are no problems, I think it’s better to start by checking for external factors first.
There is no flow meter for the oil volume in the branch line, and there is no noticeable change in the oil level indicated by the oil sight glass； The oil analysis is satisfactory. Changes that meet certain criteria will have an impact on the temperature of the fluid; the lower the value in question, the higher the temperature ； The probe is fine; the bearings that were replaced earlier show no signs of wear, and after 2 years of use, the alloy layer has not peeled off significantly. What exactly do external factors refer to?
By external factors, I mean those other reasons that cause an increase in bearing temperature without the need to remove the equipment for inspection – in other words, the factors mentioned earlier. What was the normal operating temperature before, and why does it rise when the load remains unchanged? How is the expansion of the cylinder block, and is there any deviation in the bearing housing?
The bearing shell clearance is too small, resulting in burnt carbon deposits after operation for some time. Scrape off the carbon deposits at those points, and increase the gap by 3–5 threads
Actually, the most significant issue with this type of equipment is that, over time, problems with the rotor’s dynamic balance can arise. Only this problem is the root cause of all the other issues. As for the oil quality issue, modern oil filters use filters with extremely high precision, so there should be no problems. Regarding bearings, no problems will arise as long as it’s not a normal startup. The only situation in which damage to the bearings can occur is when there is a imbalance in dynamic balance. For reference.
Was the bearing replaced before the temperature of the bearing bush increased? Additionally, was there any sudden change in the trend of the bush temperature rising or falling? If there were such sudden changes or a rapid drop in temperature, it indicates that carbon buildup has occurred on the bearing bush. Remedial measures: 1. Adjust the clearance of the bearing bush; 2. Increase the oil return volume by adding grooves to the oil baffle (due to poor oil return); 3. Replace the lubricating oil (even though it passes the analysis criteria, its service life has been too long, and the formed coating leads to carbon buildup on the bearing bush)
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Is there any carbon buildup on the surface? If so, please contact me; we specialize in removing such buildup using online equipment, and we have many successful cases of resolving issues related to increased temperature in bearing shells caused by carbon buildup.
At present, the vibration of the unit is relatively stable. Will poor dynamic balance be directly reflected in vibration problems? It still only affects Vavin. Could you provide some relevant cases for us to learn from together?
Previously, there was a sudden increase in temperature, jumping from 97°C to 103°C, and it is still showing a gradual upward trend at present. The oil analysis results are satisfactory; the lubricant was replaced in November 2018, and it has been in use for two and a half years now. What is typically the service life of 46# turbine oil?