Abstract: The analysis and detection on turbine oil for Unit 4 are carried out in consideration of the bearing bush erosion in a power plant. It concludes from the analysis and detection that the turbine oil quality deterioration and bearing bush erosion are mainly caused by the heated and oxidized oil in operation. Another cause is the poor thermal oxidation stability of the new oil. Therefore, multi-aspect discussion on the maintenance of turbine oil quality in service is taken, which includes strict new oil exam, unit overhaul enhancement, lubricating oil system defects elimination and the oil supervision and maintenance improvement to. The discussion is toenhance the oil management and maintenance, and ensure the safety and economy of the unit operation.

Key words: turbo-generator, bearing bush erosion, turbine oil, thermal oxidation stability, operation and maintenance