联合循环机组汽轮机液压螺栓螺母脱落事件分析和处理  

Analysis and Treatment of Nut of Hydraulic Bolt Fall off for Steam Turbine of Combined Cycle Unit

作　　者：王庆韧 甘地 Wang Qingren;Gan Di(Guangdong Huizhou LNG Power Co.,Ltd.,Guangdong Province Gas Turbine Power Generation Engineering Technology Research Center,Guangdong Huizhou 516082,China)

机构地区：[1]广东惠州天然气发电有限公司广东省燃气轮机发电工程技术研究中心,广东惠州516082

出　　处：《燃气轮机技术》2023年第1期46-51,共6页Gas Turbine Technology

基　　金：国家科技重大专项(2017-III-0006-0031);黑龙江省杰出青年科学基金项目(JC2018012);黑龙江省“百千万”工程科技重大专项—增材制造在舰船动力装备领域的示范应用(2019ZX03A03);船舶与海洋工程动力系统国家工程实验室—海洋工程燃气轮机实验室。

摘　　要：某联合循环机组汽轮机轴承盖振异常,威胁机组安全稳定运行,影响电网调度的灵活性。通过振动特征分析及现场实际测试,确认了振动的真实性。基于经验及紧急排查,排除了大轴弯曲。通过振动趋势分析以及盘车状态下全面排查,排除了汽流激振与轴系动平衡不良,表明缸内发生较重的转动部件松脱的可能性很小。基于低压缸特征通流面积法和汽缸进汽流量-进出口压差算法,预判低压缸内部通流间隙无变化。停止盘车后,揭开轴承箱护罩,发现汽轮机低-发联轴器有一个液压螺栓的螺母脱落。更新液压螺栓与螺母并加大紧力后,起机非常顺利。这验证了液压螺栓的螺母脱落是引发轴承盖振大的直接原因。随后深入讨论了液压螺栓螺母脱落的根本原因,确定了处理措施,提出了改进建议。Abnormal Vibration of steam turbine bearing cover occurred in a combined cycle unit,which threatened the safe and stable operation of unit,and affected the flexibility of power grid dispatching.The authenticity of vibration was confirmed through vibration characteristics analysis and site test.Based on experience and urgent investigation,ruled out bending of shaft.Through vibration trend analysis and comprehensive investigation under the turning state,excluded the causes of steam flow excitation and shafting dynamic balance badness,and regarded low possibility of the loose of heavy rotating parts in the cylinder.Based on characteristic flow-through area method of the low pressure cylinder and the algorithm of inlet flow-inlet pressure difference,forecasted little change on flow-through clearance of the low pressure cylinder.After stopped turning,uncovered the bearing box cover,found a nut of hydraulic bolts fall off,then replaced with new hydraulic bolts and nut and enlarged the torque.After the overhaul,started the unit smoothly.In the end,verified the nut of the hydraulic bolts fall off as direct cause of the vibration abnormally large on bearing cover.Then deeply discussed the reasons of the nut fall off,decided the measures,and put forward suggestions for improvement.

关 键 词：联合循环 汽轮机 液压螺栓螺母 脱落 分析处理 

分 类 号：TK14[动力工程及工程热物理—热能工程]