高等学校化学学报2024，Vol.45Issue(5)：71-80,10.DOI:10.7503/cjcu20240052
基于分子动力学的热化学储能过程中CaO/Ca(OH)2分子扩散机制研究
Study on Diffusion Mechanism of CaO/Ca(OH)2 Molecules During Thermochemical Energy Storage Process Based on Molecular Dynamics
摘要
Abstract
In CaO/Ca(OH)2 energy storage process,the energy storage and mechanical performance are related to the structure of CaO grains.This work investigated the lattice structure and molecular motion of CaO/Ca(OH)2 grains during CaO/Ca(OH)2 energy storage process using molecular dynamics simulations.The result indicates that during the dehydration stage,the movement of Ca(OH)2 molecules is consistent with the bulk diffusion mechanism.The diffusion pre-exponential factor for O/H atoms is 7.9×10‒8 m2/s,while that for Ca atom is only 4.7×10‒8 m2/s.The rapid diffusion of O/H destroys the original lattice structure,leading to a reduction in the crystallinity of CaO after dehydration.In the hydration stage,the diffusion pre-factor for outer molecules of CaO grains is 3.2×10‒8 m2/s,which is 2.5 times higher than that of inner molecules.Consequently,the molecular motion of CaO molecule is consistent with the surface diffusion mechanism.The diffusion strength of CaO molecule is weak during the hydration stage,resulting in minimal impact on the CaO lattice structure.The simulation determines the diffusion mechanisms of CaO/Ca(OH)2 molecules in the thermochemical energy storage process.This is crucial to understand the crystal structure evolution of CaO-based materials in CaO/Ca(OH)2 energy storage process.关键词
氧化钙/氢氧化钙热化学储能/氧化钙晶粒/机械性能/分子扩散/分子动力学模拟Key words
CaO/Ca(OH)2 thermochemical energy storage/CaO grains/Mechanical performance/Molecular diffusion/Molecular dynamics simulation分类
化学化工引用本文复制引用
房意,李英杰,张友浩,任宇,韩奎华,赵建立..基于分子动力学的热化学储能过程中CaO/Ca(OH)2分子扩散机制研究[J].高等学校化学学报,2024,45(5):71-80,10.基金项目
国家自然科学基金(批准号:52276204)资助. Supported by the National Natural Science Foundation of China(No.52276204). （批准号:52276204）
