汽轮发电机组轴系扭振与蒸汽力矩相互影响的研究

Study on the Interaction of the Torsional Vibration to the Steam Torsion Acting on the Steam Turbine Rotor

推导了轴系发生扭振时蒸汽力扭矩的表达式,利用该式可研究汽轮发电机组轴系上的蒸汽力矩与扭振的相互影响。对建立的模型进行了仿真计算。仿真计算表明:当汽轮机上发生扭振时,蒸汽力矩将发生波动,波动的频率与扭振的频率相同,但相位却滞后90°,即蒸汽的作用力矩将对扭振起阻尼作用;当扭振振幅增大时,蒸汽力矩的波动幅度也随之成正比地增大;单位蒸汽流量反动式汽轮机的蒸汽力矩波动幅度小于冲动式汽轮机的蒸汽力矩波动幅度;扭振发生时,速度比也将发生小幅度的波动。

The steam torque formulae used for turbine-generator when torsional vibration occured was derived in this paper. By formulae, the research on the interaction of the torsional vibration to the steam torque acting on the turbine rotor can be done. The simulation about the formulae had been done by computer. It is shown that the steam torque would wave when the torsional vibration occured. The wave frequency of the steam torque is same as the torsional vibration's but the phase angle lag 90 degrees, namely the steam torque works as damper on torsional vibration. The wave scope of the steam torque is in the positive proportion to the torsional vibration. For the wave scope of the steam torque of unit flow of steam, the reaction type turbine's is less than the impulse type turbine's. Meanwhile, the speed ratio would wave in the small scale when torsional vibration occured.