CEFR冷阱结构设计改进及热工水力分析  

Structure Innovation and Thermal-hydraulics Analysis for Cold Trap of CEFR

作　　者：陈祖国[1] 许义军[1] CHEN Zuguo;XU Yijun(China Institute of Atomic Energy,P.O.Box 275-33,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院反应堆工程技术研究部,北京102413

出　　处：《原子能科学技术》2019年第5期830-835,共6页Atomic Energy Science and Technology

基　　金：国家科技重大专项CFR600能力建设专项之F202钠回路调试项目资助(169609)

摘　　要：冷阱是中国实验快堆(CEFR)运行过程中的重要设备之一,在净化反应堆系统中的冷却剂钠、保证反应堆安全稳定运行等方面起着重要作用。而目前CEFR现有冷阱在使用过程中存在着杂质沉降效率低,易造成冷阱堵塞而使冷阱更换频繁等问题,对CEFR的长期稳定运行非常不利。分析冷阱出现的问题,可能有两方面原因:一是钠在冷阱中的流动路径不合理,易造成区域的堵塞;二是在丝网密度和布置方面,没有采用分区布置也容易使杂质沉积在外层而堵塞流道。针对这两方面的原因,本文提出了现有冷阱的改进方案,从结构设计和水力学两方面来改善冷阱内钠中杂质的沉降模式,达到延长冷阱运行寿命的目的。改进方案主要是将丝网区内筒孔封闭约1/3,并在丝网上部支撑板上开两排导流孔,以改进流场;同时将丝网分成上、中、下3个区域布置,每个区域的丝网采用不同的密度,以满足杂质从冷阱底部开始逐渐沉积的要求。通过对该方案三维建模与数值分析,并与CEFR现有冷阱的分析结果进行比较发现,改进冷阱流场分布更为合理,丝网的布置也更能符合杂质沉积的要求,后续将与CEFR的实际运行工况做进一步的比较研究。As one of the significant equipment of China Experimental Fast Reactor (CEFR) operation system,the cold trap plays an important role on purifying the coolant sodium and ensuring safety and steady operation of reactor.Currently,the existing cold trap of CEFR has some problems which include the aggradation efficiency of impurity is low,the wire mesh is blocked easily,and the cold trap is replaced frequently and so on,and these problems have a bad influence on the long-term operation of CEFR.The reasons for these problems in the current cold trap including: One is the unreasonable flow route of sodium,which can cause the partial blocking in specific area,and the other is about the density and disposal of wire mesh,which can make the aggradation of impurity easy in exterior area leading to block the flow channel.According to the reasons,a modified project was proposed to improve the aggradation pattern of impurity in terms of structure design and hydraulics,and consequently extend the operation lifetime of cold trap.The modified project as follows: About 1/3 rates of orifices on interior canister were occluded in wire mesh area,and two rows of orifices were drilled on upside support shell,thus improving the velocity distribution.Synchronously,the wire mesh was separated to three areas which were top area,middle area and bottom area respectively,and the different densities of wire mesh were used to different areas to fulfill the requirement that the aggradation pattern of impurity was from bottom to top.Through 3D modeling and numerical analysis to the project,and comparing the results to current cold trap of CEFR,it can be concluded that the modified velocity distribution is more reasonable than before,and the new disposal of the wire mesh can also meet the aggradation requirement of impurity.Further correlative study will be done according to the actual operation condition of CEFR.

关 键 词：快堆 冷阱 结构改进 热工水力 

分 类 号：TL33[核科学技术—核技术及应用]