630MW机组低压末级长叶片水蚀分析及预防  

Analysis and Prevention of Water Erosion on Final Stage Blade in Low-pressure Cylinder of 630 MW Units

作　　者：王维英 李卫军 冯立国 顾正皓 干忠明 马思聪 WANG Weiying;LI Weijun;FENG Liguo;GU Zhenghao;GAN Zhongming;MA Sicong(Guoneng Zhejiang Ninghai Power Generation Co.,Ltd.,Ningbo Zhejiang 315612,China;State Grid Zhejiang Electric Power Co.,Ltd.Research Institute,Hangzhou 310014,China;E.Energy Technology Co.,Ltd.,Hangzhou 310012,China)

机构地区：[1]国能浙江宁海发电有限公司,浙江宁波315612 [2]国网浙江省电力有限公司电力科学研究院,杭州310014 [3]杭州意能电力技术有限公司,杭州310012

出　　处：《浙江电力》2022年第4期89-95,共7页Zhejiang Electric Power

基　　金：国网浙江省电力有限公司科技项目(5211DS21003);杭州意能电力技术有限公司科技项目(EPRD2020-06)。

摘　　要：大型汽轮机低压缸末几级普遍选用自带冠长叶片,可显著提高汽轮机的性能。随着机组在低负荷工况下运行时间增加,可能出现严重水蚀现象,致使叶冠受损或脱落,威胁机组安全。针对某厂2台630 MW汽轮机组低压缸末级动叶和导流环水蚀故障现象,分析诱发原因,采取对末级动叶进行超音速热喷涂、更换空心静叶、降低8A和8B低压加热器的疏水孔位置、提高低压排汽导流环的强度等综合措施,大幅提高了低压缸的抗水蚀能力。对大型汽轮机组低压缸水蚀进行监测、及时采取综合性的预防措施,可提高机组低压缸的可靠性。Shrouded blades that are widely used in the final stage of low-pressure cylinder of large steam turbines can significantly improve the performance of the units.After long low-load operation,they are susceptible to water erosion which damages or results in falling off of the tips,and thus threatens the safe operation of the units.In view of the water corrosion failure of the low-pressure last stage blade and guide ring of a 630 MW unit in a power plant,the reasons were analyzed,and measures such as ultrasonic thermal spray of the final stage rotor blade,replacing hollow stator blade,lowering the drain holes of low-pressure heaters 8A and 8B and improving the strength of the low-pressure exhaust guide ring were taken,which greatly improved the water erosion resistance ability of lowpressure cylinder.The preliminary results show that the reliability of low-pressure cylinder of large steam turbine unit can be improved by monitoring the water corrosion of low-pressure cylinder and timely taking comprehensive preventive measures.

关 键 词：自带冠叶片 水蚀 喷涂 空心静叶 疏水 

分 类 号：TK263.3[动力工程及工程热物理—动力机械及工程]