反应堆吊篮振动特性边界条件研究

Research on Vibration Characteristics Boundary Condition of Core Barrel of Nuclear Reactors

对秦山核电厂二期600 MW反应堆及CAP 1400反应堆空吊篮在空气中和静水中振动特性的边界条件进行研究。吊篮结构采用实体建模,流体结构采用流体单元模拟。本研究分别用弱贴紧、中度贴紧和强贴紧来模拟法兰与容器支承台阶之间不同的贴紧状态,用弱摩擦、中度摩擦和强摩擦模拟法兰与容器支承台阶之间受到的不同摩擦力。研究表明,秦山核电厂二期600 MW反应堆空吊篮在静水中的边界条件比空气中的强,CAP 1400反应堆空吊篮在空气中与静水中的边界条件一致;压紧弹性环的预紧力和吊篮法兰所受到的摩擦力对吊篮结构固有频率有一定影响。

Boundary condition of vibration characteristics both in air and still water about the empty core barrel of Qinshan Nuclear Plant 600 MW reactor and CAP 1400 type reactor were investigated. The structure of core barrel was modeled by solid element, and the fluid structure was simulated by fluid element. The close effect between the flange of core barrel and support step of reactor pressure vessel was assumed with three types of boundary conditions： weak close, medium close and strong close. At the same time, the friction between the flange of core barrel and support step of reactor pressure vessel was assumed with three types of boundary conditions： weak friction, medium friction and strong friction. The research shows that： The boundary condition of core barrel in still water is much stronger than that in air for Qinshan Nuclear Plant 600 MW reactor, but the boundary condition of core barrel both in still water and in air is the same for CAP 1400 type reactor. The preload of hold down spring and friction of flange have a certain effect on the core barrel frequency.