600MW汽轮机低压缸动力学特性分析与结构优化  

Dynamic Characteristics Analysis and Structural Optimization for LP Casing of 600MW Steam Turbine

作　　者：张一鸣 徐自力[1] 陈贝贝[2] 杨灵[2] ZHANG Yi-ming;XU Zi-li;CHEN Bei-bei;YANG Ling(State Key Laboratory for Strength and Vibration of Mechanical Structures,School of Aerospace Engineering,Xi'an Jiaotong University,Xi'an 710049,China;Dongfang Turbine Co.,Ltd.,Deyang 618000,China)

机构地区：[1]西安交通大学航天航空学院/复杂服役环境重大装备结构强度与寿命全国重点实验室,西安710049 [2]东方电气集团东方汽轮机有限公司,德阳618000

出　　处：《汽轮机技术》2024年第3期179-182,共4页Turbine Technology

摘　　要：针对某600MW凝汽式汽轮机低压缸盖振较大的问题,从动力学特性理论分析入手,采用三维有限元方法对低压缸结构进行了模态分析,提出了一种与低压转子旋转激振力等效的双向简谐力加载方法,对低压缸的受迫振动响应进行了数值计算;基于计算结果分析,提出了低压缸的结构优化改进方案,并从多角度对所提方案进行了效果评估。结果表明,低压缸的下缸刚度较低导致固有频率落入50Hz附近,以及转子轴承支撑中心距离端板较远导致激励力力矩较大,是低压缸振动较大的主要原因;提出的结构优化方案可提高低压缸的固有频率,使其避开50Hz工作频率,同时也能够有效降低振动响应的幅值。Aiming at the large vibration of the LP casing of a 600MW condensing steam turbine,the modal analysis of the LP casing structure is conducted using the three-dimensional finite element method.To simulate the rotating excitation of the LP rotor,a two-way simple harmonic force loading method is proposed.The forced vibration response of the LP casing is then determined through numerical calculations.A scheme for optimizing the structure is suggested through analysis of the findings,and the efficacy of this proposed scheme is assessed from various perspectives.The results demonstrate that the natural frequency falls close to 50Hz due to the low stiffness of the lower casing,and the rotor bearing support centre is a considerable distance from the end plate,causing a substantial excitation moment.These factors are the primary contributors to the large vibration of the LP casing.The proposed structural optimization scheme can improve the natural frequency of the LP casing,thereby keeping away from the 50Hz operating frequency,and also effectively reduce the amplitude of the vibration response.

关 键 词：汽轮机 低压缸 模态分析 振动响应 结构优化 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]