格架松弛对燃料棒湍流激励及微振磨损的影响研究  

Effect of Grid Relaxation on Turbulence Excitation and Fretting Wear of Fuel Rod

作　　者：齐欢欢[1] 冯志鹏[1] 姜乃斌[1] 黄茜[1] 黄旋[1] QI Huanhuan;FENG Zhipeng;JIANG Naibin;HUANG Qian;HUANG Xuan(Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China,Chengdu 610041,China)

机构地区：[1]中国核动力研究设计院核反应堆系统设计技术重点实验室,四川成都610041

出　　处：《原子能科学技术》2018年第10期1810-1816,共7页Atomic Energy Science and Technology

基　　金：国家自然科学基金资助项目(51606180)

摘　　要：假设所有支承有效,基于燃料棒模态分析的结果,根据压水堆燃料棒的流场分布特征,采用功率谱密度表征湍流激励,结合相关功率谱密度试验参数,求解了各阶模态的振动位移均方值,基于ARCHARD磨损公式计算了燃料棒刚凸位置的磨损深度。由于制造工艺、运输、辐照的影响,格架对燃料棒的夹持作用可能松弛。依次假设格架单个刚凸及弹簧松弛,研究了松弛对燃料棒模态、流致振动以及磨损的影响。结果表明:格架弹簧的松弛对固有频率的影响可忽略;原振幅较大的位置附近刚凸松弛对固有频率影响明显;堆芯入口及出口的横向流速较大,燃料棒底部和顶部的湍流激励振幅较大,这些位置的刚凸支承松弛使湍流激励振幅明显增大,中间位置的刚凸支承松弛对振幅影响较小;刚凸支承松弛对磨损深度的影响与对湍流激励最大振幅的影响趋势基本一致。磨损除了与湍流激励振幅相关,还与固有频率相关,顶部振型和频率乘积的影响大于底部格架位置,顶部格架刚凸松弛对磨损影响最大。Assuming that all supports were valid,based on the results of fuel rod modal analysis,according to the flow field distribution characteristics of PWR fuel rods,the power spectral density was used to characterize the turbulence excitation.Combining the correlation power spectral density test parameters,the mean square value of the vibration displacement of each mode was found,and the wear depth of dimple position of the fuel rod was calculated based on the ARCHARD wear formula.Due to the manufacturing process,transportation and irradiation,the clamping action of the grid to the fuel rods may relax.Assuming that just one single dimple or spring relaxation is in turn,the effect of grid relaxation on the fuel rod modes,flow-induced vibration and wear were studied.The results show that the relaxation of the grid spring has negligible effect on the natural frequency.The dimple relaxation near the location with larger original amplitude has a significant effect on the natural frequency.The transverse flow velocities at the inlet and outlet of the core are larger and the amplitudes of turbulent excitation at the bottom and top of the fuel rods are larger when all supports are valid.When dimple relaxes in these locations the amplitude of turbulence excitation will obviously increase.The effect of dimple support relaxation in the middle position on amplitude is less.The effect trend of dimple support relaxation on the depth of wear is basically the same as the effect on the maximum amplitude of turbulence excitation.In addition to the amplitude of turbulence excitation,the wear is also related to the natural frequency.The effect of multiplying the top mode and frequency is greater than that of the bottom grid,so the top grid dimple relaxation has the greatest effect on the wear.

关 键 词：燃料棒 刚凸 格架松弛 流致振动 微振磨损 

分 类 号：TL352[核科学技术—核技术及应用]