联合循环深度调峰汽轮机低压末级叶片断裂故障分析  

Fracture Fault Analysis of Low Pressure Last Stage Blade of Combined Cycle Steam Turbine Unit under Deep Peaking Regulation

作　　者：武茂松 俞聪 孟凡垟 亓军锋 WU Maosong;YU Cong;MENG Fanyang;QI Junfeng(Hua Dian Electric Power Research Institute Co.,Ltd.,Hangzhou,China,310030)

机构地区：[1]华电电力科学研究院有限公司,浙江杭州310030

出　　处：《热能动力工程》2024年第6期185-190,198,共7页Journal of Engineering for Thermal Energy and Power

摘　　要：针对某深度调峰联合循环汽轮机组低压末级叶片断裂故障问题,通过叶片材料和裂纹断口理化检验及试验分析,结合机组深度调峰运行特点,深入分析了叶片断裂故障发生的原因,并给出了改进建议。分析表明:由于深度调峰燃气机组长期处于盘车运行的特殊工况以及盘车转速设置偏高导致汽轮机低压末级松装叶片叶根部位产生磨损,进而导致叶片松动,在高速盘车过程中叶片相互猛烈撞击,造成了叶片叶顶围带及叶片的损伤;在汽轮机启动过程中离心力的作用下叶片产生断裂,断裂残骸落入末级动叶和静叶之间,进而对整圈末级叶片造成严重损伤;当盘车转速由50 r/min降至3 r/min后,机组末级叶片运行良好,未发生叶根磨损松动的情况。Aiming at the fracture fault problem of low pressure last stage blade of a combined cycle turbine unit under deep peaking regulation,this paper analyzed the causes of blade fracture deeply through physical and chemical inspection and test analysis of blade material and crack fracture,combined with the characteristics of deep peaking operation of the unit,and gave relevant improvement suggestions.Analysis shows that because the deep peaking gas unit is in the special working condition of turning gear for a long time,the high turning speed setting causes the loose-fitting blade of the low pressure last stage to wear out at the root of the blade,causing the blade to loose.In the process of high-speed turning gear,the blades violently collide with each other,causing damage to the blade tip shroud and blade;the fracture occurs under the action of centrifugal force during the steam turbine startup,and the fracture debris falls between the last stage rotor blade and the stator blade,causing serious damage to the last stage blade of the whole circle.After the turning gear speed of the unit reduces from 50 r/min to 3 r/min,the last stage blade of the unit is in good condition,and no accidents of similar blade loosening or blade root wear have occurred.

关 键 词：联合循环 深度调峰 松装叶片 轴向移位 叶片断裂 

分 类 号：TM621[电气工程—电力系统及自动化]