西门子9F燃机轴系异常振动分析与处理

Analysis and Treatment of Abnormal Vibration of a Siemens 9F Gas Turbine Generator Unit

某西门子9F燃气轮机自基建以来一直存在6号和8号轴承振动问题,严重威胁到机组安全稳定运行。6号轴承在SSS离合器啮合或脱扣期间发生振动突变,以低频分量为主,诊断为油膜失稳。8号轴承受支撑结构设计、安装条件及运行工况等影响造成支撑刚度偏低,在冷态启动下瓦振爬升明显,接近跳机值。通过抬高轴承标高、减少轴承长径比、中低压缸猫爪负荷调整等一系列措施和尝试后,治理彻底解决了西门子9F燃气轮机轴系异常振动问题,为解决业内西门子9F燃气轮机类似振动问题提供了借鉴。

A Siemens 9F gas turbine had vibration problem of No. 6 and No. 8 bearing since its construction, which seriously threatens the safe and stable operation of the unit. The vibration of NO.8 bearing suddenly increased during the engagement or release of the SSS clutch, which was mainly low frequency component, and was diagnosed as the oil whirl. Due to the structure design, installation conditions and operation conditions, which results in low supporting stiffness of NO.8 bearing. The vibration of NO.8 bearing increased obviously in cold start-up, which was close to the jumper value. After a series of measures and attempts such as raising the bearing elevation, reducing the bearing length, adjusting the cat-claw load of middle-low pressure cylinder and so on, the problem of abnormal vibration of SIEMENS 9F gas turbine shaft system has been solved thoroughly, which provides reference for similar vibration problems.