液态重金属冷却剂晃动响应特性研究

Study on sloshing response characteristics of liquid heavy metal coolant

铅基堆采用液态重金属冷却剂并具有池式布局的特点,与传统压水堆中冷却剂密度低、回路式布局相比,地震载荷作用下重金属冷却剂晃动对反应堆容器和堆内结构产生的冲击和振动模式显著不同。本文基于双向流固耦合的有限元方法,开展液态重金属反应堆的载液堆本体的地震响应分析,研究冷却剂类型、支撑形式和高径比等因素对堆容器内冷却剂晃动效应的影响。计算结果表明:液态重金属相对轻质冷却剂,其地震响应非等比增加,流体动力粘度对大尺寸反应堆的流固耦合作用不显著;不同支撑方式在支撑处有应力集中,整体表现为梁式振型对支撑方式不敏感;不同充液比激发的振动模态类似,充液比越小,最大应力强度点越往底封头集中。这些结果可为液态重金属反应堆的结构安全设计提供参数化依据。

[Background] Compared with the traditional pressurized-water reactor (PWRs) with low density coolant and loop layout, the lead-based reactor uses liquid heavy metal coolant and has the characteristics of pool layout.[Purpose] This study aims at the impact and vibration modes of heavy metal coolant's sloshing to the reactor vessel and its internal components under a load of seismic.[Methods] First of all, two-way fluid-structure coupling finite element method was applied to the seismic response analysis of liquid heavy metal reactor. Then the sloshing effect of coolant type, the support form, as well as the height-diameter ratio on the sloshing effect of coolant in the reactor container, were calculated and analyzed.[Results] The calculation results show that the seismic response of liquid heavy metals is not equal to that of light coolant, and the fluid-dynamic viscosity is not significant for fluid-solid coupling of large-scale reactors. The different support forms have stress concentration at the support position and the overall performance is that the beam mode is not sensitive to the support form. The vibration modes stimulated by different liquid-filled ratios are similar, and the smaller the liquid-filled ratio, the more concentrated the maximum stress intensity point are on the bottom head.[Conclusion] These results provide a parametric basis for the structural safety design of liquid heavy metal reactors.