Molecular dynamics simulation of solar salt (NaNO3-KNO3) mixtures
Molecular dynamics simulation of solar salt (NaNO3-KNO3) mixtures
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DOI：
10.1016/j.solmat.2019.04.019
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发表时间：
2019-09-15
影响因子：
6.9
通讯作者：
Ding, Y.
中科院分区：
文献类型：
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作者：
Anagnostopoulos, A.;Alexiadis, A.;Ding, Y.
熔盐在聚光太阳能发电（CSP）装置中具有扩展的应用，既作为传热材料又作为能量存储材料。在这项研究中，引入了一组Lennard-Jones原子间参数来模拟NaNO 3和KNO 3，以及它们最常用的工业混合物，即所谓的太阳盐（60%NaNO3 - 40%KNO3）。局部结构研究通过径向分布函数。此外，从熔化到分解温度的密度，导热系数，自扩散系数，粘度和表面张力的计算，并与实验数据进行比较。局部结构计算与现有的和提出的原子间相互作用势，并发现是非常一致的。此外，密度、粘度和表面张力与文献数据存在微小差异。热导率的绝对值接近报告的数据，但趋势值得怀疑。最后，自扩散系数从测量值下降，但在趋势方面是相似的。结果被认为是在良好的协议。这项工作代表了第一次扩展验证的努力，在高温下使用Lennard-Jones势模拟熔融硝酸盐及其混合物，提供了新的工具，可以帮助在分子尺度上对熔融盐结构的基本理解。
Molten salts have extended applications in concentrated solar power (CSP) installations, both as heat transfer and energy storage materials. In this study, a set of Lennard-Jones interatomic parameters are introduced for simulating NaNO3 and KNO3, as well as their most frequently industrially used mixture the so-called solar-salt (60% NaNO3 - 40% KNO3). Local structures are studied via radial distribution functions. Furthermore, density, thermal conductivity, self-diffusivity, viscosity and surface tension are calculated, from melting to decomposition temperature, and compared with experimental data. The local structures are calculated with both existing and presented interatomic potentials and are found to be in excellent agreement. Additionally, density, viscosity and surface tension present minor differences from literature data. Thermal conductivity, in terms of absolute values is in the proximity of reported data but is questionable in terms of trend. Finally, self-diffusion coefficients declinate from measured values, but are similar in terms of trend. Results are found to be in good agreement. This work represents the first extended validated effort in modelling molten nitrate salts and their mixtures at elevated temperatures using a Lennard-Jones potential, providing new tools that can aid in the fundamental understanding of molten salt structures at the molecular scale.