Lubricating oil pressure and oil temperature adjustment For unstable rotors where oil film instability has occurred, properly lower the lubricating oil temperature and increase the viscosity of the lubricating oil, which is beneficial to increase the damping coefficient of the oil film and reduce the rotor amplitude. Similarly, increasing the oil supply pressure of the lubricating oil can facilitate the formation of the oil wedge, increase the stiffness of the oil film, and effectively suppress the vibration of the rotor. In the failure treatment of the YL3000 type flue turbine oil film instability vibration, we reduce the lubricating oil pressure from 0.9kg/cm2, reduce the lubricating oil temperature from 42°C to 38°C, and the oil film vibration of the unit is obviously reduced. After 24 hours operation, the oil film The stability returned to normal and the unit was successfully put into use.

Bearing preload adjustment In the bearing maintenance work, the correct preload of the bearing bush can be adjusted to effectively prevent the oil film from being unstable. The preload value of the bearing bush is adjusted to be positive, that is, the radius of curvature of the inner surface of the bearing bush is greater than the radius of the inner circle of the bearing. At this time, the journal faces the inner surface of the bearing shell to increase the eccentric moment, so that the degree of convergence of the oil wedge on each block is greater, forcing the lubricating oil to enter the converging gap and increasing the oil wedge force, thereby effectively improving the oil film. stability. Reducing the bearing clearance and reducing the bearing clearance actually increases the eccentricity of the bearing. From the above analysis, it can be known that increasing the eccentricity of the bearing can increase the load bearing characteristics of the bearing and increase the rotational speed of the oil film.

Through the diagnosis of two typical oil film instability problems caused by the YL3000 flue gas turbine and SPEG4 air pressure turbine of the above-mentioned catalytic plant of Wuhan Petrochemical Plant, the oil film loss of the multi-oil wedge bearing was analyzed in detail from the aspects of bearing force analysis and characteristic parameter calculation. Stable fault mechanism and treatment methods, and draw the following conclusions: 1 In the high-speed light-load rotor-bearing system, the multi-oil wedge bearing oil film has high stability, but there may still be oil film instability vibration failure; 2 oil film The characteristic frequency of the unstable vibration is 0.40.5 times the power frequency, accompanied by the frequency doubling response; 3 adjusting the lubricating oil pressure, oil temperature, adjusting the bearing preload, bearing clearance, etc. can effectively prevent the occurrence of bearing oil film vibration failure. We also treated the steam lines in the control system and added the line condensing facilities. Ensure that the steam enters the sealed chamber completely in a gaseous state, avoiding the problem of water hammer.