某300MW亚临界汽轮机高压隔板导流环脱落的分析与处理  

Treatment on the Loss of High Pressure Diaphragm Guide in 300MW Sub-critical Steam Turbine

作　　者：李冰心 韩志勇 骆贵兵[1] 刘丽春[1] 张志博[1] LI Bing-xin;HAN Zhi-yong;LUO Gui-bing;LIU Li-chun;ZHANG Zhi-bo(Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710049,China;Baotou Third Thermal Power Plant,North United Power Co.,Ltd.,Baotou 014040,China)

机构地区：[1]西安热工研究院有限公司,西安710049 [2]北方联合电力有限责任公司包头第三热电厂,包头014040

出　　处：《汽轮机技术》2024年第4期303-306,278,共5页Turbine Technology

基　　金：中国华能集团有限公司科技项目(HNKJ22-H144)。

摘　　要：某300MW亚临界汽轮机运行期间出现调节级压力升高17%~20%、轴向位移增大等异常情况,无法满足机组满负荷运行要求。揭缸检查发现高压第二级隔板外导流环与隔板连接的连接螺栓全部断裂,脱落的导流环堵塞隔板进汽通道,通流面积减小导致调节级压力升高。通过宏观形貌观察、化学成分、金相检验以及运行工况等分析导流环螺栓断裂原因,结果表明:螺栓为金属疲劳断裂;螺栓材质在部分工况下无法满足机组运行期间调节级后最高温度要求,使用温度裕度偏低;运行期间隔板变形将对螺栓产生剪切力。为避免此类型机组再次出现导流环脱落问题,提出了相应的建议。During the operation of the DTC 300MW sub-critical steamturbine,there were abnormal problem of the working pressure after regulating stage increased by 17%-20%and the unit only operated at low load,which can not meet the requirements of the unit's full load operation.It was found that all the fastening bolts connecting the outer guide of the second high pressure stage partition and the partition were broken.The lost guide blocked the inlet passage of the diaphragm,and the flow area decreased,resulting in the pressure increase of the regulation stage.The reasons for bolt fracture of the diaphragm guide was studied by macroscopic morphology,chemical composition,metallographic inspection and operating conditions.The results show that the reason for bolt fracture is fatigue fracture.The bolt material can not meet the requirements of the highest temperature after regulating stage during operation under some working conditions.The operating temperature margin of bolts is low.The deformation of the partition during operation will cause shear force on the bolt.In order to avoid this type of unit to encounter the problem of diaphragm guide falling off again,the suggestions are put forward.

关 键 词：汽轮机 调节级压力 隔板导流环 紧固螺栓 

分 类 号：TK268[动力工程及工程热物理—动力机械及工程]