Abstract: The shaft vibration of NO.3 bearing suddenly raised from 80 μm to 240 μm in an imported 600 MW supercritical power plant. At the same time, the temperature of NO.2 bearing raised to 106 ℃. The excessive vibration and temperature have already threaded the safety of the unit. In order to find out the cause of the vibration fault, several experiments were carried out on the unit, including changing the oil hydraulic, load and vacuum of the condenser. Experimental results show that the forward reasoning method is valid for finding out the cause of vibration and the example provided in this paper is useful for analyzing similar vibration fault in supercritical power plant.

Key words: supercritical unit, vibration, fault