【摘要】 气体水合物是一种包络状晶体,在能源勘探、二氧化碳捕集和封存、海水淡化及空调蓄冷等领域均有潜在的应用价值。稳定性研究能够确定水合物稳定存在的热力学区间,方便水合物在各个领域内应用。然而,通过宏观实验研究很难精确的控制和分析水合物的稳定性及分解特性。本文采用分子动力学模拟,在微观角度研究了构型不同、客体分子不同的情况下,气体水合物稳定性的差异,从径向分布函数、均方位移、F₃序参数三个方面进行了探讨。发现对于CO₂气体水合物,I型结构更加稳定;CO₂和环戊烷二元水合物的稳定性优于CO₂水合物,为水合物的宏观实验研究和工程应用积累了理论基础。更多还原

【Abstract】 Gas hydrate is an enveloped crystal and has potential applications in energy exploration, carbon dioxide capture and storage, seawater desalination and in air conditioning as a cold storage medium. The stability study can determine the thermodynamic interval of hydrate and facilitate the application in various fields. However, it is difficult to accurately control and analyze the stability and decomposition characteristics of hydrate through macroscopic experimental research. In this paper, molecular dynamics simulations are utilized to study the difference of gas hydrate stability with different configurations and guest molecules from the microscopic perspective, and it is discussed from three aspects: radial distribution function, mean square displacement and F₃ order parameter. It was found that the type I structure of CO₂ gas hydrate was more stable than structure II. The stability of binary hydrate（CO₂+ cyclopentane） is better than that of single CO₂ hydrate, which provides the theoretical foundation for the macroscopic experimental study and engineering application of hydrate.更多还原