氯化物熔盐单质及其混合物热物性子动力学模拟研究

杨薛明; 刘杰庭; 崔吉祥; 张明理; 孟凡星

doi:10.19912/j.0254-0096.tynxb.2021-0525

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太阳能学报 ›› 2022, Vol. 43 ›› Issue (11) : 433-442. DOI: 10.19912/j.0254-0096.tynxb.2021-0525

氯化物熔盐单质及其混合物热物性子动力学模拟研究

杨薛明¹, 刘杰庭¹, 崔吉祥², 张明理¹, 孟凡星¹

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MOLECULAR DYNAMICS SIMULATION RESEARCH OF THERMOPHYSICAL PROPERTIES OF CHLORIDE MOLTEN SALTS AND THEIR MIXTURES

Yang Xueming¹, Liu Jieting¹, Cui Jixiang², Zhang Mingli¹, Meng Fanxing¹

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摘要

采用分子动力学模拟的方法对3种常用的氯化物熔盐单质（KCl、NaCl和LiCl）、二元混合氯化物熔盐（LiCl-KCl和 LiCl-NaCl）和三元混合氯化物熔盐（KCl-LiCl-NaCl）的比热容、粘度和热导率进行系统研究。研究中粘度采用平衡分子动力学方法进行计算,而热导率采用非平衡分子动力学方法进行计算。结果表明,3种氯化物熔盐单质的比热容模拟值与实验值相比误差均在6.8%以内;NaCl、KCL、LiCl熔盐单质的粘度平均误差分别为5.3%、10.9%以及11.7%;热导率除了LiCl外,其余两种氯化物熔盐的热导率误差均在9%以下。与文献不同混合比例的NaCl-KCl的热导率平衡分子动力学方法模拟值比较,偏差均在12.5%以内。综合结果表明模拟结果均与实验值表现出较好的一致性。为了更好地从微观结构上理解氯化物熔盐的热物性,通过计算径向分布函数对熔融盐体系及局部结构进行分析。

Abstract

Comprehensive molecular dynamic simulations were carried out to compute the thermophysical properties of three commonly used chloride molten salts and their binary and ternary mixtures over a wide operating temperature range. The viscosities were calculated by the equilibrium molecular dynamics （EMD） method, and the thermal conductivities were calculated by the non-equilibrium molecular dynamics method. Compared with the experimental data, the absolute relative errors of the simulation results of the specific heat capacities for the three kinds of chloride molten salts are all within 6.8%. The simulated viscosities differ from the experimental data by 5.3%, 10.9%, and 11.7% for NaCl, KCl and LiCl, respectively. Except for LiCl, the averaged absolute relative errors of thermal conductivity for NaCl and KCl compared to the experimental data are less than 9%. Compared with the previous EMD study results, the absolute relative deviations of the thermal conductivities of the binary mixed KCl-NaCl chloride salts are within 12.5%. The results showed that the simulation results are in good agreement with the experimental values. To better understand the thermophysical properties of chloride molten salt at a molecular level, the partial radial distribution functions were calculated and local structures were analyzed.

导出引用

杨薛明, 刘杰庭, 崔吉祥, 张明理, 孟凡星. 氯化物熔盐单质及其混合物热物性子动力学模拟研究[J]. 太阳能学报. 2022, 43(11): 433-442 https://doi.org/10.19912/j.0254-0096.tynxb.2021-0525

Yang Xueming, Liu Jieting, Cui Jixiang, Zhang Mingli, Meng Fanxing. MOLECULAR DYNAMICS SIMULATION RESEARCH OF THERMOPHYSICAL PROPERTIES OF CHLORIDE MOLTEN SALTS AND THEIR MIXTURES[J]. Acta Energiae Solaris Sinica. 2022, 43(11): 433-442 https://doi.org/10.19912/j.0254-0096.tynxb.2021-0525

中图分类号： TK121

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