Molecular dynamics simulation of structure and thermal properties of LiCl-KCl molten salt nanofluids

doi:10.19799/j.cnki.2095-4239.2022.0683

Abstract

Abstract:

Herein, the molecular dynamics method investigates the effects of Al₂O₃ nanoparticles on the structure and thermophysical properties of binary chloride salt LiCl-KCl. Furthermore, the effect of doping amount and temperature on radial distribution function, coordination number [N(r)], self-diffusion coefficient(D), density, viscosity, and thermal conductivity of nanofluids were analyzed. The results show that in the temperature range of 700～1400 K, with increasing nanoparticles, the first peak position of the radial distribution function g_Li-Cl(r) moves to the left gradually, the peak height and the coordination number increase, and the self-diffusion coefficient decreases gradually. The density, viscosity, and thermal conductivity of nanofluids decreased with increasing temperature but increased with increasing nanoparticles, and the maximum viscosity and thermal conductivity increased by 16.83% and 4.95%, respectively. The change in thermophysical properties was attributed to adding Al₂O₃ nanoparticles that reduced the distance between anions in the nanofluids, enhancing the association effect, and making the melt structure more compact.

Key words: molten salt, Al₂O₃, microstructure, thermophysical property, molecular dynamics

CLC Number:

TK 02

Heqing TIAN, Zhaoyang KOU, Junjie ZHOU, Yinsheng YU. Molecular dynamics simulation of structure and thermal properties of LiCl-KCl molten salt nanofluids[J]. Energy Storage Science and Technology, 2023, 12(3): 654-660.

Figures/Tables 8

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Table 1

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Pair	A_ij /(kcal/mol)	ρ_ij /nm	σ_ij /nm	C_ij /(nm⁶·kcal/mol)	D_ij /(nm⁸·kcal/mol)
Li-Li	9.7266	0.03425	0.1632	1.0504×10^-6	0.4317×10^-8
Li-K	7.689	0.03396	0.2279	1.91641×10^-5	1.22097×10^-7
Li-Cl	6.687	0.03425	0.2401	2.87769×10^-5	3.45326×10^-7
K-K	6.0782	0.03367	0.2926	3.49639×10^-4	3.453225×10^-6
K-Cl	4.8626	0.03367	0.3048	6.90645×10^-4	1.050356×10^-5
Cl-Cl	3.6473	0.03402	0.317	1.6757854×10^-3	3.3659592×10^-5
Al-Al	0.066783	0.0068	0.15704	3.23548×10^-4	0
Al-O	0.172715	0.0164	0.26067	7.9621×10^-4	0
O-O	0.276344	0.0263	0.3643	1.959372×10^-3	0

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