介孔内太阳盐凝固特性的尺度效应和结构效应分析  

Influence of mesoporous size and structure on heat transport characteristics of mixed nitrate

作　　者：毛蕊 杨启容[1] 李昭莹 闫晨宣 何卓亚 Mao Rui;Yang Qi-Rong;Li Zhao-Ying;Yan Chen-Xuan;He Zhuo-Ya(College of Mechanical and Electrical Engineering,Qingdao University,Qingdao 266071,China;State Key Laboratory of Polysaccharide Fiber-forming and Ecological Textile,Qingdao University,Qingdao 266071,China;Qingdao Institute of Bioenergy and Process,Chinese Academy of Sciences,Qingdao 266101,China)

机构地区：[1]青岛大学机电工程学院,青岛266071 [2]青岛大学生物多糖纤维成形与生态纺织国家重点实验室,青岛266071 [3]中国科学院青岛生物能源与过程研究所,青岛266101

出　　处：《物理学报》2022年第11期41-52,共12页Acta Physica Sinica

基　　金：青岛大学青年卓越科研启动经费(批准号:QDPYHT-5-065)资助的课题。

摘　　要：采用分子动力学方法模拟介孔尺度和结构对太阳盐凝固特性的影响.使用Material Studio软件分别建立不同尺度、两种结构的混合硝酸盐模型,模型通过Lammps进行模拟计算,总结凝固点、过冷度、相变潜热随尺度和结构的变化规律,利用径向分布函数、势能-温度曲线、吉布斯自由能等表征参量对介孔内太阳盐凝固特性的微观机理进行分析.结果表明,太阳盐的凝固点随着纳米孔尺度的增大先增大后减小最终趋于稳定,相同尺度下纳米线结构的凝固点高于纳米颗粒的凝固点.太阳盐的过冷度整体呈现随介孔尺度增大而减小的规律,但有反常增加现象.两种不同结构下,太阳盐凝固焓随着尺度增大均逐渐增大,且纳米线结构较纳米粒子结构在相同尺度下提高了30%—37%.The effects of mesoporous size and structure on the solidification characteristics of solar salt are simulated by molecular dynamics(MD).The mixed nitrate model with different scales and two structures is established by using Material Studio software,and the model is applied to the Lammps software package for simulation calculation.The changes of freezing point,supercooling,and phase transformation latent heat are summarized.The micro mechanism of solidification characteristics of nano solar salt is analyzed by radial distribution function,potential energy temperature curve and Gibbs free energy theory.The results show that the freezing point of solar salt first increases and then decreases with the increase of nanopore scale.The nanowire structure will also increase the phase transition temperature on the same scale,and the phase transition points of the two eventually tend to be stable with the increase of scale.The supercooling of solar salt decreases with the increase of mesoporous scale,but there is an abnormal increase.Under the two different structures,the solidification enthalpy gradually decreases with the increase of scale,and the phase transition latent heat of nanowire solar salt is 30%-37%higher than that of nanoparticle structure on the same scale.

关 键 词：太阳盐 尺度 过冷度 凝固特性 

分 类 号：TB383.1[一般工业技术—材料科学与工程]