控制棒下行运动特性影响因素分析

液体悬浮式非能动停堆技术是近年来核反应安全领域的研究热点之一，研究控制棒下行的运动特性对核电厂的安全运行有着重要意义。本文选取2种典型非保护瞬态失流事故（ULOF）为依据设计多种工况进行模型实验，结合实验数据对控制棒下行运动进行受力分析得出其阻力的时程变化。通过控制变量法对比分析了控制棒尾部出流孔径和初始周向位置对控制棒下行运动时程及缓冲效果的影响，并得出了下行时的阻力系数与雷诺数之间的函数关系。本研究可为优化控制棒组件结构提供依据，给控制棒下行运动受力研究中阻力系数的选取提供参考。 

Analysis of Influencing Factors of Control Rod Downward Motion Characteristics

Liquid suspension passive shutdown technology is one of the research hotspots in the field of nuclear reaction safety in recent years. It is important to study the downward motion characteristics of control rods for the safe operation of nuclear power plants. Two typical unprotected transient loss of flow accidents (ULOF) were selected as the basis to design various working conditions for model experiments. Combined with the experimental data, the force analysis of the downward motion of the control rod was carried out to obtain the time-history change of its resistance. The influence of outlet aperture and initial circumferential position on the time history and buffering effect of the control rod was analyzed by the control variable method, and the function relationship between resistance coefficient and Reynolds number was obtained. It can provide the basis for optimizing the structure of control rod assembly and the selection of resistance coefficient in the study of the downward motion force of control rod.