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During operation, the rotor of a turbine is subjected to the centrifugal force generated by its high-speed rotation； Axial force exerted by steam on the rotor impeller, shaft shoulder, and steam seal shoulder ； The dynamic stress generated therein by rotor vibration ； Thermal stress caused by uneven temperature inside the rotor ； Torque for transmitting mechanical power. The centrifugal force generated by rotation is proportional to the square of the rotational speed ； The axial force exerted by the steam on the impeller is proportional to the area of the impeller and the pressure difference of the steam on its two sides ； The axial force exerted by steam on the shaft shoulder is proportional to its area and the pressure of the steam at that location ； The dynamic stress generated by rotor vibration is proportional to the amplitude and frequency of the vibration; the higher the vibration frequency and the greater the amplitude, the greater the dynamic stress ； The thermal stress within the rotor is related to the temperature difference between the inner and outer walls of the rotor as well as the axial temperature difference; the greater the temperature difference, the greater the thermal stress ； The torque used to transmit mechanical power is proportional to the load on the unit, with the torque being greatest when the generator is short-circuited. Excessive centrifugal force will cause the resulting stress to exceed the allowable value, and in severe cases this can lead to the rotor spinning out of control ； The combined axial force is too large, causing the thrust bearings to bear an axial load that exceeds their capacity; as a result, these bearings burn out due to excessive temperature, which leads to the disappearance of the axial clearances in the turbine, thereby causing friction or blade failure ； Excessive dynamic and thermal stresses in the rotor can cause the resultant stress to exceed the allowable value, accelerating fatigue of the material. This leads to cracks at the stress-concentrated areas of the rotor, reducing its service life and even resulting in fracture ； Excessive rotor vibration causes the dynamic and static clearances to disappear, leading to friction that results in rotor bending and further intensified vibration ； The torsional vibration of the rotor and the torque used to transmit mechanical power generate shear stress within the rotor. If this stress becomes excessive, especially when torsional vibration of the rotor reaches resonance, it can cause the bolts connecting the couplings to break, leading to serious accidents. As long as the overspeed protection is functioning properly during operation, the speed will be kept at no more than 120% of the rated speed ； The generator is equipped with short-circuit protection ； By controlling the rate of steam temperature rise and the load increase within allowable limits, it is possible to ensure the safe operation of the rotor and extend its service life. This post was last edited by 156026692 on 2009-2-2 23:41]