吴宏岩　金佳佳　杨建伟　董康乐

【摘 要】永磁钠流量计是用于实现钠冷快堆钠流量测量的关键仪表，而磁路设计是永磁钠流量计研制的核心任务。本文针对中国示范快堆工程钠流量测量需求，计算确定了DN80永磁钠流量计磁路设计目标，完成了材料选择以及磁路结构和关键尺寸的设计。利用ANSYS仿真软件分析了磁路中的磁场分布情况，初步验证磁路设计的可行性。根据设计的磁路结构完成了5台磁钢的加工，并对充磁及高温稳定性处理后的磁场特性进行了实测。结果表明：ANSYS仿真与实测结果仅相差4.06mT，而且5台磁钢经稳定性处理后的磁感应强度均满足不小于51mT的使用要求。

【关键词】永磁钠流量计；钠冷快堆；磁路设计；ANSYS仿真

中图分类号： TG386.32 文献标识码： A 文章编号： 2095-2457（2018）08-0015-004

Design and Verification of Magnetic Circuit for

DN80 Permanent-Magnet Sodium Flow Meter

WU Hong-yan JIN Jia-jia YANG Jian-wei DONG Kang-le

（China Institute of Atomic Energy，Beijing 102413，China）

【Abstract】Permanent magnet flow meter is the key instrument to realize sodium flow measurement in sodium cooled fast breeder reactor. According to the measuring requirements of China Demonstration Fast Reactor，the design goal of the magnetic circuit for DN80 flow meter is confirmed through calculation and analysis. The material selection，as well as structure and critical dimensions design are also completed.The simulation magnetic field distribution is obtained by ANSYS，and preliminarily verified the feasibility of the magnet circuit design.On the basis of the design，five pieces of magnet were manufactured，and magnetic characteristic measurements were taken after magnetization and temperature stabilization.The results indicate that the error between simulation and measurement is only 4.06mT，and all the magnetic flux density measured after stabilization meet the requirements of no less than 51mT.

【Key words】Permanent-magnet sodium flow meter；Sodium cooled fast breeder reactor；Magnetic circuit design；ANSYS analysis

0 引言

鈉流量是钠冷快堆安全经济运行的重要参数，由于具有结构简单、输出信号强、线性度好、耐高温和对流体流动特征不敏感等优点，永磁钠流量计在国际各快堆试验回路和反应堆中得到广泛应用[1-2]。当前国内市场无可供商用的永磁钠流量计出售，中国实验快堆（CEFR）中安装的永磁钠流量计均为进口设备。为满足中国示范快堆（CFR600）工程建造的需求，永磁钠流量计的研制工作已开展，而决定流量计测量精度和可靠性的关键则是设计一个合理而稳定的磁路。

1 永磁钠流量计结构及原理

永磁钠流量计结构示意图如图1所示。永磁体、磁轭、磁极构成闭合磁路，在磁极气隙间为永磁钠流量计提供工作磁场。……