Lube Oil Leak or Bearing Damage?

The above incident indicates that your air turbine has a mechanical imbalance and an oil flow anomaly.

Your post indicates that you don't know what happened or how to evaluate the problem.

Call someone who can fix your air turbine. You'll need the make and model of the defective unit.

We can't fix it from here.

What does the compressor manufacturer's service department say?

This is not a gas turbine. This is a steam turbine manufactured by harbin turbine company.

Sorry. My mistake.

Now that the manufacturer's know, call them.

It sound as though bearing 3 has lost some material, causing oil to bypass its usual flow path and resulting in less overall pressure. (This would resemble losing part of a rod bearing liner in a piston engine and blowing oil into the crankcase.)

It's definitely time to call the turbine manufacturer and arrange a site visit bya Service Technician, since the facility doesn't have the capability of diagnosis and troubleshooting. Today/this morning/within the hour isn't too soon. Unless the facility can do without the 170MW turbine for several months while a replacement is procured, manufactured, shipped, installed and commissioned, perhaps?

I'll only address the oil pressure... yes it could have dropped from a leak, but it can also drop if one of your clearances gets to large...which indicates damage. since you did n't provide a picture we have no idea where the pressure is actually be taken, it could be on a feeder line, it could be on the bearing housing, etc. ask concise and complete questions and you might just get exact and helpful responses

It appears the bearing 3 has lost babitt and its oil clearance has increased resulting in increased oil flow. This has reduced the pressure of oil as well as reduce the drain oil temperature since most of the oil is by passing the bearing pressure area. It is time to check the bearing 3. Check babbit condition, oil clearance . Try to analyze root cause why this has happened?

Check the quality of oil ,the flow meter, the filters,coupling and pump. When there is a lubrication problem Beijing gare the first to suffer.. Manke checklist based on manufactrer recommandation

It sounds like your bearing is starting to fail. Get your Operations and Maintenance crew on the problem. It sounds like you have the instrumentation or diagnostic equipment installed or available. If your crew is unable to replace the bearing then contract with a reputable company or the manufacturer to repair this. With all the turbines I've repaired, Most of the time when there was an increase in vibration it was a bearing issue. The other issue that could be the culprit and easily checked is the alignment of the turbine shaft to the generator shaft. Make sure the coupling is tight and in good condition and the shafts are properly aligned. Has there been any drastic change in temperature where the turbine is housed? Have you changed any processes? When was the last oil change? Did you change lubrication manufacturers? Is 170 MW close to the maximum of your turbine? How close is turbine 3 to turbine 4? There are so many variables. Start with the simple things.

1. Check your coupling.
2. Check shaft alignment.
3. Use a portable vibration sensor to verify the instrumentation.

Keep it simple.
If those are good then you are looking at possible bearing failure.