针对某厂带有SSS离合器的300 MW级“凝汽-抽汽-背压”（NCB）式汽轮机纯凝运行模式下的轴系振动故障，进行了振动矢量计算、轴瓦温度分析和可倾瓦工作原理分析。计算与分析发现，振动是由高中压转子残余不平衡量、轴瓦载荷较轻、轴瓦瓦块调节性能差等多因素导致。提出提高轴瓦载荷、更换轴瓦瓦块并进行现场轴系动平衡的振动处理方案。运行结果表明：与振动处理前相比，高中压转子高压排汽侧支撑瓦的振动波动现象消失；在汽轮机空负荷工况下，高中压转子高压排汽侧支撑瓦X向通频振动由118 μm降低至20 μm。

For the shafting vibration fault problem of the 300 MW condensingextractionback pressure (NCB)steam turbine with SSS clutch in a power plant in the mode of pure condensation, the vibration vector calculation, bearing shell temperature analysis and working principle analysis of the tilting pad were carried out respectively. Through the calculation and analysis, it is found that the vibration is caused by many factors,such as the residual imbalance of high and intermediumpressure rotors, low bearing shell load, poor adjustment performance of bearing shell and so on.The vibration treatment scheme is proposed to enhance the bearing shell load, replace the bearing shell and perform the onsite dynamic balancing of the shafting. The operation result shows that compared with that one before vibration treatment, the vibration wave phenomenon of bearing shell on the side of HP steam exhaust of high and intermediumpressure rotor disappears. Under the working condition of empty load of steam turbine, its direct vibration frequency in X direction is reduced from 118 μm to 20 μm.

TK221