抽凝式汽轮机推力轴瓦超温与通流异常的分析处理

Analysis and Treatment of Thrust Bearing Bush Over-temperature and Abnormal Flow of Extraction Condensing Steam Turbine

汽轮机在运行中出现推力轴瓦超温、轴向位移增大等异常问题,分析发现机组通流部分工作参数偏离设计值,调节级后工作压力明显升高,机组只能低负荷运行。通过揭缸检查,汽轮机中压级的通流部分结垢严重,主要成分为硅酸钠盐;汽水取样分析发现,化水中的SiO 2含量超出标准值23倍,是导致蒸汽携带高含量硅酸钠盐的根本原因;提出了增强化水前置过滤除硅的方案,严格监督电站汽水达标运行,经除垢修复后,机组重新启动恢复正常运行。

During steam turbine operation,there were abnormal problem of thrust bearing bush over-temperature and increased axial displacement,the analysis showed that the operation parameters of flow path deviate from the design value,the working pressure after regulating stage increased significantly and the unit only operated at low load.Through the inspection after cylinder opening,there were seriously salt fouling found at middle pressure stages with main component of sodium silicate,the steam and water sampling analysis was carried out and showed that the demineralized water had 23 times SiO 2 content exceeding the standard value,which is the root reason cause the high silica salt content in steam and carried into steam turbine.It is proposed to enhance the pre-filtration of chemical water treatment for silica removal and strictly monitor to the steam and water quality during power station running,the steam turbine restarted and put back to normal operation after removal of the salt fouling.