某电厂汽轮机低压缸零出力供热工况低压末级叶片动强度分析  

Dynamic strength analysis of the low pressure last stage blade under zero-output heating conditions of low pressure cylinder in a power plant

作　　者：谷伟伟[1] 张永海[1] 余小兵[1] 高庆 高登攀[1] 宋文希[1] GU Weiwei, ZHANG Yonghai, YU Xiaobing, GAO Qing, GAO Dengpan, SONG Wenxi(Xi ＇an Thermal Power Research Institute Co., Ltd., Xi＇an 710054, Chin)

机构地区：[1]西安热工研究院有限公司,陕西西安710054

出　　处：《热力发电》2018年第5期63-70,共8页Thermal Power Generation

摘　　要：汽轮机低压缸零出力供热工况下,低压缸的进汽流量急剧减小,会导致低压末级叶片运行工况严重偏离设计值而影响其安全性。本文采用有限元方法,建立了某电厂300 MW汽轮机低压末级叶片在汽流激振力下的振动方程,采用直接积分方法分别计算了叶片在设计工况和低压缸零出力供热工况下的动应力。结果表明:设计工况下叶片的最大动应力为5.973 MPa,位于叶顶区域;低压缸零出力供热工况下叶片的最大动应力为1.119 MPa,位于凸肩区域,该最大动应力小于设计工况,说明低压缸零出力供热工况下叶片的动强度满足制造厂设计要求。The steam input flow of low pressure cylinder under zero-output heating conditions is decreased sharply, which causes the last stage blade to seriously deviate from the design value and then affects its safety. Based on the finite element method, the vibration equation of the low pressure last stage blade of a 300 MW steam turbine under steam flow excitation force is established. The dynamic stresses of the blade under the design condition and zerooutput heating conditions of low pressure cylinder are calculated separately by direct integration method. The calculation results show that the maximum dynamic stress under the design condition is 5.973 MPa, which is located in the tip region of the blade. On the other hand, the maximum dynamic stress under zero-output heating conditions of low pressure cylinder is 1.119 MPa, which is located in the shoulder region. The dynamic stress under zerooutput heating conditions of low pressure cylinder is less than that under the design condition, indicating that the dynamic strength of the blade under zero-output heating conditions of low pressure cylinder meets the design requirements of the manufacturer.

关 键 词：汽轮机 低压缸零出力供热 叶片 有限元方法 振动方程 动应力 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]