Control system for adjusting the temperature of bearing oil for the purpose of minimizing rotor vibrations

A method for reducing rotor vibrations in a system, in particular a variability thereof, in a shafting, in particular a turbine shafting, said method comprising:

• measuring a temperature of a bearing of a shaft;
• and
• adjusting a temperature of oil supplied to the bearing to a temperature as assigned as an output variable in an allocation for minimized rotor vibrations with the measured temperature of the bearing as the input variable, wherein the temperature of the oil supplied to the bearing is adjusted by a valve, with the valve and the bearing being part of an oil circuit;
• further comprising combining an output of an oil cooler and a bypass of the oil circuit, with the bypass bypassing the oil cooler and connected to the mixing valve and the valve being disposed in the bypass;
• for initial assignment with different temperatures of the bearing,
• measuring the rotor vibrations,
• calculating the respective oil temperatures of the bearing for minimizing the rotor vibrations,
• storing the respective oil temperatures of the bearing as input variables, and
• storing the associated calculated bearing oil temperatures as output variables in the assignment;
• and
• obtaining empirical values from an operating history of the shafting, and storing the empirical values in the assignment as output variables, so that damping at an early stage is enabled and inertia is compensated.

An oil circuit in a system, in particular a variability thereof, in a shafting, in particular a turbine shafting, the oil circuit comprising:

• a bearing for support of a shaft;
• a bearing oil tank;
• a pump supply oil from the bearing oil tank to the bearing;
• an oil cooler;
• a bypass bypassing the oil cooler and having a valve configured to adjust a temperature of the oil supplied to the bearing;
• a mixing valve fluidly connected to the oil cooler and the bypass to combine an output of the oil cooler and the bypass;
• a control system for reducing rotor vibrations, said control system configured to measure the temperature of the bearing, and to adjust a temperature of oil supplied to the bearing to a temperature as assigned as an output variable in an allocation for minimized rotor vibrations with the measured temperature of the bearing as the input variable;
• for initial assignment with different temperatures of the bearing,
• measuring the rotor vibrations,
• calculating the respective oil temperatures of the bearing for minimizing the rotor vibrations,
• storing the respective oil temperatures of the bearing as input variables, and
• storing the associated calculated bearing oil temperatures as output variables in the assignment;
• and
• obtaining empirical values from an operating history of the shafting, and storing the empirical values in the assignment as output variable, so that damping at an early stage is enabled and inertia of the system is compensated.