汽轮机转子轮盘加工跳动量引起的振动特性研究

Research on the Vibration of Steam Turbine Rotor Caused by DiscRoundness Error

汽轮机转子不可避免存在加工误差,轮盘加工误差引起的径向跳动量在转子结构上产生质量偏心,进而导致汽轮机运转过程中转子的不平衡振动,影响汽轮机组的振动噪声特性。分析了汽轮机转子轮盘径向跳动的谐波特性,建立了轮盘质量偏心量与径向跳动谐波项之间的关系式,进而分析了轮盘加工跳动量对转子振动幅值的影响规律。结果表明,轮盘径向跳动的1阶谐波量与轮盘质量偏心呈线性关系,而跳动的高阶谐波量对轮盘偏心量无影响。轮盘加工误差引起的转子振动幅值与轮盘径向跳动的1阶谐波量成正比。研究结果为从加工制造方面降低汽轮机组振动噪声水平提供了理论依据。

Steam turbine rotor is inevitably having manufacture error,the roundness error of the discs of steam turbine rotor will lead to an eccentricity of mass about the axis,which finally causes the unbalance vibration of rotor and affects the noise level of the unit.In this paper,the harmonic characteristic of the radial error of steam turbine rotor disc was analyzed,and the expression of the disc mass eccentricity with the harmonicamplitude of the roundness error was established.The vibration of rotor caused by the roundness error of disc was investigated.Results show that the eccentricity of disc mass is linear with the first order of harmonic amplitude of roundness error,while the higher orders of roundness error harmonic amplitude have no effect on the mass eccentricity of disc.The amplitude of rotor vibration caused by disc roundness error varies linearly with the first order harmonic amplitude of disc roundness error.The results in this work could be a theoretical reference for the reduction of steam turbine from the aspect of manufacture.