Ab-initio molecular dynamics study on thermal property of NaCl–CaCl2 molten salt for high-temperature heat transfer and storage
Journal
Renewable Energy
Journal Volume
163
Pages
579-588
Date Issued
2021
Author(s)
Abstract
NaCl–CaCl2 molten salt is considered as a promising high-temperature heat transfer and storage fluid for advanced nuclear power plants and concentrating solar power plants in the field of renewable energy utilization. However, the comprehensive physical properties and their microscopic mechanisms for the molten NaCl–CaCl2 are failed to be measured accurately due to the extremely measuring condition. In this work, the ab-initio molecular dynamics simulation is used to investigate its microstructures and thermophysical properties for entire operating temperatures. It reveals that ion clusters are formed in terms of three for face-sharing, two for edge-sharing, and one for corner-sharing Cl? ions between the coordination shells of two neighboring cations. The coordination numbers of Na+-Cl- and Ca2+-Cl- ion pairs decrease from 5.88 to 6.46 at 783 K to 5.33 and 6.02 at 1173 K respectively. Meanwhile, the reliable and meaningful values of densities, ion self-diffusion coefficients, viscosities, and thermal conductivities were evaluated from 783 to 1173 K. It suggests that the distances and interactions between ions pairs determine thermodynamic properties directly. The ab-initio molecular dynamics simulation is proved to be an effective way to obtain the essential data for the designs of heat transfer and thermal energy storage systems in practical applications. ? 2020 Elsevier Ltd
Subjects
Diffusion in liquids; Digital storage; Energy utilization; Fused salts; Heat storage; Heat transfer; Ions; Molecular dynamics; Nuclear fuels; Sodium chloride; Solar power plants; Temperature; Thermal conductivity; Ab initio molecular dynamics; Ab initio molecular dynamics simulation; Advanced nuclear power plants; Concentrating solar power plant; High temperature heat transfer; Microscopic mechanisms; Operating temperature; Thermal energy storage systems; Nuclear power plants; energy storage; high temperature; molecular analysis; physical property; power plant; salt; sodium chloride
SDGs
Other Subjects
Diffusion in liquids; Digital storage; Energy utilization; Fused salts; Heat storage; Heat transfer; Ions; Molecular dynamics; Nuclear fuels; Sodium chloride; Solar power plants; Temperature; Thermal conductivity; Ab initio molecular dynamics; Ab initio molecular dynamics simulation; Advanced nuclear power plants; Concentrating solar power plant; High temperature heat transfer; Microscopic mechanisms; Operating temperature; Thermal energy storage systems; Nuclear power plants; energy storage; high temperature; molecular analysis; physical property; power plant; salt; sodium chloride
Type
journal article