铅铋冷却绕丝燃料组件横流特性分析  

Analysis of Transverse Flow Characteristics in LBE-cooled Wire-wrapped Fuel Assembly

作　　者：丛腾龙 王俊杰 肖瑶 刘茂龙 顾汉洋[1] CONG Tenglong;WANG Junjie;XIAO Yao;LIU Maolong;GU Hanyang(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《原子能科学技术》2022年第12期2725-2734,共10页Atomic Energy Science and Technology

基　　金：国家自然科学基金(11705035);黑龙江省优秀青年科学基金(YQ2020A003)。

摘　　要：准确预测绕丝棒束通道内的横向流动特性是开展铅铋冷却快堆热工水力安全分析的基础。本文采用数值模拟的方法分析了液态铅铋工质下单绕丝和多绕丝燃料组件内的横流特性。分析结果表明,单绕丝组件的中心子通道横流流速最大不超过主流流速的19%,且横流方向和二次流中心随着高度周期性变化;单绕丝组件中,当绕丝与子通道交界面重合或垂直时,中心子通道界面横向流量和横流交混指数趋于零或达到峰值;在单绕丝组件结构一定的情况下,横流交混指数在湍流区对Re不敏感,而与组件结构参数存在较大相关性;多绕丝组件中心子通道界面上的横流存在两个相反的流向。LBE-cooled fast reactor(LBFR) has a promising application prospect in energy generation and transmutation of high-level radioactive waste. Wire-wrapped fuel rods are usually used in LBFR to reach high heat transfer efficiency and self-support. The wire spacer has a great influence on the transverse flow and inter-channel mixing, and leads to a non-uniform temperature profile over the fuel rod surface. Therefore, accurate prediction of the transverse flow mixing characteristics in the wire-wrapped bundle channel is the basis of thermal-hydraulic safety analysis of LBFR. In the present study, a CFD modeling and simulation for a LBE-cooled 7-pin wire-wrapped fuel assembly was carried out based on RANS method. The simulation results were firstly compared with the experimental data from the literature. A good agreement demonstrated the capability of the employed approach to predict the flow field in the rod bundle. Then, the three-dimensional transverse flow mixing behaviors of LBE in single wire-wrapped fuel and multi wire-wrapped fuel assemblies were analyzed in detail. The results show that the maximum transverse flow velocity in the central sub-channel of the single wire-wrapped fuel assembly does not exceed 19% of the axial flow velocity. The transverse flow direction and secondary flow center change periodically with height. In the single wire-wrapped fuel assembly, the transverse flow at the interface of the central sub-channel is distributed as a trigonometric function along the axis. When the wire spacer coincides with the interface of the central sub-channel, the transverse flow and the transverse flow mixing index tend to zero. When the wire spacer is perpendicular to the interface, the transverse flow and the transverse flow mixing index reach the peak. The transverse flow mixing index is not sensitive to Reynolds number in the turbulent zone, but is strongly correlated to the structural parameters of the assembly, which means that the lateral mixing in the wire-wrapped bundle is dominated by the flow swee

关 键 词：铅铋快堆 绕丝燃料组件 交混特性 子通道分析 

分 类 号：TL33[核科学技术—核技术及应用]