文献类型：期刊文献

中文题名：LiF-BeF2熔盐微观结构及扩散特性的分子动力学研究

英文题名：Molecular dynamics investigation on microstructure and diffusion properties of LiF-BeF molten salt

作者：贺国达[1,2,3];汤睿[1,2];段学志[4];谢雷东[1];傅杰[1,2];戴建兴[1];钱渊[1,2];王建强[1,2,5]

机构：[1]中国科学院上海应用物理研究所,上海201800;[2]中国科学院微观界面物理与探测重点实验室,上海201800;[3]中国科学院大学,北京100049;[4]华东理工大学化学工程联合国家重点实验室,上海200237;[5]中国科学院洁净能源创新研究院,辽宁大连116023

年份：2020

卷号：71

期号：8

起止页码：3565

中文期刊名：化工学报

外文期刊名：CIESC Journal

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：中国科学院战略性先导科技专项(XDA02010000,XDA21000000);中国科学院青年人才专项(Y929021031)。

语种：中文

中文关键词：LiF-BeF2熔盐;分子模拟;微观结构;扩散;电导率

外文关键词：LiF-BeF2 molten salt;molecular dynamics;microstructure;diffusion;conductivity

摘要：LiF-BeF2熔盐作为熔盐堆的冷却剂及核燃料溶剂近年来备受关注,其扩散行为与核燃料的相容性和结构材料的腐蚀性密切相关。采用Car-Parrinello分子动力学模拟研究了LiF-BeF2熔盐的微观结构及基于此结构的扩散行为。研究结果表明Be2+具有较强的络合能力,易形成中性网络聚合体,且其数量随温度的增加而减少;液态LiF-BeF2熔盐中除了包含聚合体,还包含游离的F^-、Li^+、BeF3^-和BeF4^2-,而非完全游离的F^-、Li^+和Be^2+。基于此微观结构获得的自扩散系数及电导率与实验结果吻合较好,且电导率随温度变化符合Arrhenius模型,而不是目前文献认为的无限稀释溶液的线性模型。
LiF-BeF2 molten salt has been paid much attention in recent years as a coolant and nuclear fuel solvent for molten salt reactor,and its diffusion behavior is closely related to the compatibility of nuclear fuel and the corrosion of structural materials.In this paper,Car-Parrinello molecular dynamics simulation was used to investigate the microstructure and diffusion behavior of LiF-BeF2 melts.The results show that Be2+has a strong complexation ability to form neutral clusters,and its number decreases with the increase of temperature.Liquid LiF-BeF2 consists of neutral clusters and free F^-,Li^+,BeF3^-and BeF4^2-,rather than completely free F^-,Li^+and Be^2+.The self-diffusion coefficient and conductivity obtained based on this microstructure are in good agreement with the experimental results,and the change of conductivity with temperature conforms to the Arrhenius model,rather than the linear model of infinitely diluted solutions considered in the literature.