典型调速工况大功率液力偶合器叶轮装配体强度分析

随着大型核/火电站装机容量的大幅度增加,大功率液力偶合器作为电站系统主锅炉给水泵调速的核心元件,其工作叶轮的强度成为影响电站系统安全稳定运行的重要因素.文章以某型液力偶合器叶轮装配体为研究对象,采用单向流固耦合计算方法,建立全流道流固耦合分析模型,其中泵轮与涡轮套的端面定位采用接触算法,用梁单元模拟螺钉联接效果,对典型工况下叶轮装配体结构强度计算分析.结果表明,装配体整体变形和应力随着转速比的增大呈增加趋势,且叶轮变形大小与对应区域旋转半径长度基本成正比,说明离心载荷是影响叶轮装配体强度的主要原因;由于螺钉预紧力效应,叶轮连接区域出现局部应力集中现象;涡轮套内缘是叶轮装配体结构强度的薄弱区域,此分析结果与文献发表结果相吻合.此项研究工作为自主大功率液力偶合器叶轮结构设计及优化提供有效的应用理论指导.

Strength Analysis of Impeller Assembly Structure of High Power Hydrodynamic Coupling under Typical Speed Regulation

With the large increase of the capacity of large nuclear / thermal power stations, high power hydraulic coupling is the core component of the main boiler feed water pump, and the strength of working impeller has become an important factor affecting the safety and stability of the power station system. In this paper, the impeller assembly body of a certain hydraulic coupler was taken as the research object. A fluid solid coupling analysis model of the full flow passage was established by the one way fluid solid coupling calculation method. The contact algorithm was used in the end face location of the pump wheel and the turbine sleeve, and the beam element was used to simulate the screw connection effect, calculation and analysis of strength of impeller assembly structure under typical working conditions. The results show that the overall deformation and stress of the assembly increase with the increase of the rotational speed ratio, and the deformation size of the impeller is basically proportional to the length of the rotation radius in the corresponding region. It shows that the centrifugal load is the main reason that affects the strength of the assembly body of the impeller, and the local stress concentration in the connection area of the impeller appears due to the screw pretightening force effect. The inner edge of the turbine sleeve is the weak area of the impeller assembly structure strength, and the analysis results are consistent with the existing results. This research work provides an effective theoretical guidance for the structural design and optimization of the impeller of the autonomous high-power hydraulic coupling.