钠冷快堆控制棒组件流量分配对温度分布影响研究  

Study on the Influence of Flow Distribution of the Control Rod Assembly on Temperature Distribution in Sodium-cooled Fast Reactor

作　　者：李新宇 张东辉 张熙司[1] 薛方元 LI Xinyu;ZHANG Donghui;ZHANG Xisi;XUE Fangyuan(China Institute of Atomic Energy,Beijing 102413,China;CNNP Xiapu Nuclear Power Co.,Ltd.,Ningde of Fujian Prov.355199,China)

机构地区：[1]中国原子能科学研究院,北京102413 [2]中国霞浦核电有限公司,福建宁德355199

出　　处：《核科学与工程》2024年第6期1294-1307,共14页Nuclear Science and Engineering

摘　　要：在典型的钠冷快堆设计中,控制棒组件出口冷却剂温度明显低于周围燃料组件出口冷却剂温度,使控制棒导向管内外温差较大,可能造成局部热应力过大,造成结构损坏,给核电厂安全运行带来隐患。拟通过改变控制棒组件流量分配方式缓解该问题,为确定不同控制棒组件流量分配对导向管及其内部冷却剂和结构材料温度分布情况,采用CFD软件FLUENT,分别对控制棒组件三种不同流量分配方案下,对应的堆芯出口区域冷却剂及连接装置进行流固共轭换热计算,并对堆芯出口区域冷却剂温度分布情况、导向管内部冷却剂及结构材料温度分布情况、导向管内外壁面轴向、周向温差分别进行分析。结果表明,流量分配越大将导致导向管壁面温差越大,从而带来热应力问题,而流量分配较小将使驱动机构与控制棒操作头处温度升高,考验材料耐热性能。获得了控制棒组件力学评价的设计输入,确定了结构部件热条件最恶劣的区域,同时验证了一种较为合理的控制棒组件流量分配方案。In the design of a typical sodium-cooled fast reactor design,the temperature of the coolant at the core outlet of the control rod assembly is significantly lower than that of the coolant at the core outlet of the surrounding fuel assembly,resulting in a large temperature difference between the inside and outside of the guide tube,which may cause excessive local thermal stress.The problem is to be alleviated by changing the flow distribution mode of the control rod assembly.In order to deter mine the temperature distribution of the guide pipe and its internal coolant and structural materials with different flow distribution modes of the control rod assembly,the CFD software FLUENT is adopted.The fluid-solid conjugate heat transfer calculation was carried out for the coolant and connecting device in the core outlet area corresponding to three different schemes of flow distribution of the control rod assembly of 3.746 kg/s,4.682 kg/s and 5.619 kg/s.The temperature distribution of coolant in the core outlet area,the temperature distribution of coolant and structural materials in the guide tube,and the temperature difference between the inner and outer walls of the guide tube are analyzed.The results show that the greater the flow distribution,the greater the temperature difference on the wall of the guide tube,the greater the thermal stress,while the smaller the flow distribution,the higher the temperature at the operating head of the drive mechanism and the control rod assembly,the test of the heat resistance of the material.The design input of the mechanical evaluation of the control rod assembly is obtained,and a more reasonable flow distribution scheme of the control rod assembly is verified.

关 键 词：控制棒导向管 热应力 CFD 共轭换热 

分 类 号：TL37[核科学技术—核技术及应用]