摘要
定子机座是水轮发电机中固定定子铁芯并支承上机架的重要部件,在结构设计中,应在保证其强度、刚度和动态特性的要求下,实现结构轻量化.以定子机座为研究对象,建立有限元模型,对强度、刚度和动态特性进行分析计算.基于结构尺寸优化设计方法,选择定子机座结构的板厚为设计变量,以正应力和刚度两种设计指标作为约束条件,对其进行以质量最小为目标的优化设计.采用复合形法进行寻优迭代,得到定子机座尺寸优化结果.轻量化设计后定子机座的最大应力及最大位移均在许用值范围内.模态分析表明:优化后结构的动态特性满足设计要求.轻量化设计使定子机座结构的质量减小了1890kg,减重率达24.2%,材料的潜力得到充分利用,实现了轻量化目标.优化结果在厂方的定子机座改进设计中得到应用,经满负荷运行及现场测试,其动力特性均满足要求.
Stator frame is an important part for fixing stator core and bearing the upper bracket in hydro generator,in its structural design,the lightweight structure should be realized under the requirement of ensuring its strength,stiffness and dynamic performance.Taking stator frame as the research object,the strength,the stiffness and the dynamic characteristics of stator frame have been calculated and analyzed by means of establishing a finite element model.Based on structure sizing optimization design method,plates thickness were selected as the design variables,and the two design indexes of normal stress and stiffness were taken as the constraint conditions to optimize the stator frame with the minimum mass as the objective.The sizing optimization of stator frame was determined by using the compound form method with optimization iteration.Through lightweight optimization design,the maximum normal stress and maximum displacement of stator frame are within the allowable value range.Modal analysis shows that the dynamic characteristics of the optimized structure meet the design requirements.The optimization design reduces the weight of stator frame by 1 890 kg and the weight-loss ratio reaches 24.2%,with the potential of material further utilized,thus achieving the purpose of lightweight.The optimization results are applied by the manufacturer in the improvement design of stator frame,and its dynamic characteristics meet the design requirements through full load operation and site test.
作者
廖永宜
廖伯瑜
LIAO Yongyi;LIAO Baiyu(Key Laboratory of Vibration and Noise under Ministry of Education of Yunnan Province,Kunming University of Science and Technology,Kunming 650500,China;Adult Education College,Kunming University of Science and Technology,Kunming 650051,China)
出处
《中国工程机械学报》
北大核心
2019年第3期215-220,共6页
Chinese Journal of Construction Machinery
关键词
定子机座
水轮发电机
有限元分析
尺寸优化
改进设计
stator frame
hydro generator
finite element analysis
sizing optimization
design improvement
