Effect of aggregation on thermal conduction in ternary molten salt-based nanofluids: insights from a multiscale coupled MD–LBM method

Molten salts serve as primary heat transfer and storage media in thermal energy storage systems. Adding nanoparticles to molten salt to create nanofluids is known to significantly improve the thermal conductivity of the molten salts. However, nanoparticle agglomeration is inevitable and substantiall...

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Main Authors: Zhe Yang, Qingsheng Yu, Ce Cui, Haowei Xing, Xiang Yin, Yulong Song, Xu Yang, Feng Cao
Format: Article
Language:English
Published: KeAi Communications Co., Ltd. 2025-03-01
Series:Energy Storage and Saving
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Online Access:http://www.sciencedirect.com/science/article/pii/S2772683524000463
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author Zhe Yang
Qingsheng Yu
Ce Cui
Haowei Xing
Xiang Yin
Yulong Song
Xu Yang
Feng Cao
author_facet Zhe Yang
Qingsheng Yu
Ce Cui
Haowei Xing
Xiang Yin
Yulong Song
Xu Yang
Feng Cao
author_sort Zhe Yang
collection DOAJ
description Molten salts serve as primary heat transfer and storage media in thermal energy storage systems. Adding nanoparticles to molten salt to create nanofluids is known to significantly improve the thermal conductivity of the molten salts. However, nanoparticle agglomeration is inevitable and substantially affects the thermal conductivity of molten salts. Moreover, the mechanisms whereby agglomeration influences thermal conductivity remain unclear. This paper presents an innovative multiscale coupling model that combines molecular dynamics (MD) simulations with the lattice Boltzmann method (LBM) to investigate the thermal conductivity of CuO nanoparticles in ternary NaCl–KCl–LiCl molten salt-based nanofluids. Both nonaggregated and aggregated states were considered. After conducting MD simulations at the microscale to examine the thermal contact resistance at the interface between nanoparticles, we employed the LBM to determine the effective thermal conductivity of the nanofluids at the mesoscale. The findings reveal the formation of significant heat flow channels in nanofluids containing nanoparticles. However, an increase in the thermal contact resistance reduces these channels in agglomerated particles, potentially reducing the thermal conductivity compared with that in the nonaggregated nanofluids. In cluster-like structures, fewer nanoparticles are positioned within heat flow channels, in contrast to chain-like arrangements. This reduction limits the enhancement in the thermal conductivity and minimizes variations in the thermal conductivity due to differences in the aggregate particle number and orientation. Furthermore, the thermal conductivity exhibited notable variations with varying agglomerated nanoparticle diameters at identical mass fractions. Both smaller and larger particles can increase the level of contact thermal resistance, ultimately reducing the thermal conductivity.
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spelling doaj-art-75f36684a18547fb9195edbeb5d857ae2025-08-20T01:54:45ZengKeAi Communications Co., Ltd.Energy Storage and Saving2772-68352025-03-0141708210.1016/j.enss.2024.11.001Effect of aggregation on thermal conduction in ternary molten salt-based nanofluids: insights from a multiscale coupled MD–LBM methodZhe Yang0Qingsheng Yu1Ce Cui2Haowei Xing3Xiang Yin4Yulong Song5Xu Yang6Feng Cao7School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, ChinaSchool of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, ChinaSchool of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, ChinaSchool of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, ChinaSchool of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, ChinaSchool of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, ChinaCorresponding author.; School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, ChinaCorresponding author.; School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, ChinaMolten salts serve as primary heat transfer and storage media in thermal energy storage systems. Adding nanoparticles to molten salt to create nanofluids is known to significantly improve the thermal conductivity of the molten salts. However, nanoparticle agglomeration is inevitable and substantially affects the thermal conductivity of molten salts. Moreover, the mechanisms whereby agglomeration influences thermal conductivity remain unclear. This paper presents an innovative multiscale coupling model that combines molecular dynamics (MD) simulations with the lattice Boltzmann method (LBM) to investigate the thermal conductivity of CuO nanoparticles in ternary NaCl–KCl–LiCl molten salt-based nanofluids. Both nonaggregated and aggregated states were considered. After conducting MD simulations at the microscale to examine the thermal contact resistance at the interface between nanoparticles, we employed the LBM to determine the effective thermal conductivity of the nanofluids at the mesoscale. The findings reveal the formation of significant heat flow channels in nanofluids containing nanoparticles. However, an increase in the thermal contact resistance reduces these channels in agglomerated particles, potentially reducing the thermal conductivity compared with that in the nonaggregated nanofluids. In cluster-like structures, fewer nanoparticles are positioned within heat flow channels, in contrast to chain-like arrangements. This reduction limits the enhancement in the thermal conductivity and minimizes variations in the thermal conductivity due to differences in the aggregate particle number and orientation. Furthermore, the thermal conductivity exhibited notable variations with varying agglomerated nanoparticle diameters at identical mass fractions. Both smaller and larger particles can increase the level of contact thermal resistance, ultimately reducing the thermal conductivity.http://www.sciencedirect.com/science/article/pii/S2772683524000463Molten salt nanofluidAggregationThermal conductivityHeat flow channelsCoupling model
spellingShingle Zhe Yang
Qingsheng Yu
Ce Cui
Haowei Xing
Xiang Yin
Yulong Song
Xu Yang
Feng Cao
Effect of aggregation on thermal conduction in ternary molten salt-based nanofluids: insights from a multiscale coupled MD–LBM method
Energy Storage and Saving
Molten salt nanofluid
Aggregation
Thermal conductivity
Heat flow channels
Coupling model
title Effect of aggregation on thermal conduction in ternary molten salt-based nanofluids: insights from a multiscale coupled MD–LBM method
title_full Effect of aggregation on thermal conduction in ternary molten salt-based nanofluids: insights from a multiscale coupled MD–LBM method
title_fullStr Effect of aggregation on thermal conduction in ternary molten salt-based nanofluids: insights from a multiscale coupled MD–LBM method
title_full_unstemmed Effect of aggregation on thermal conduction in ternary molten salt-based nanofluids: insights from a multiscale coupled MD–LBM method
title_short Effect of aggregation on thermal conduction in ternary molten salt-based nanofluids: insights from a multiscale coupled MD–LBM method
title_sort effect of aggregation on thermal conduction in ternary molten salt based nanofluids insights from a multiscale coupled md lbm method
topic Molten salt nanofluid
Aggregation
Thermal conductivity
Heat flow channels
Coupling model
url http://www.sciencedirect.com/science/article/pii/S2772683524000463
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