烃类水合物导热特性的分子动力学模拟  

Characteristic of thermal conduction in hydrocarbon hydrates using molecular dynamics method

作　　者：万丽华[1,2] 梁德青[1,2] 关进安[1,2] 

机构地区：[1]中国科学院广州能源研究所,广东广州510640 [2]中国科学院可再生能源与天然气水合物重点实验室,广东广州510640

出　　处：《化工学报》2014年第3期792-796,共5页CIESC Journal

基　　金：国家自然科学基金项目(51106163;51206169);中国科学院知识创新工程(KGZD-EW-301);国家自然科学基金-广东省联合基金项目(U0933004)~~

摘　　要：采用分子动力学模拟方法 Green-Kubo理论计算了263.15 K、3 MPa,sⅠ乙烷水合物、乙烯水合物的导热,给出密度和热导率值。从主客体分子和晶体结构(致密性、规整程度)对导热的影响等角度研究了烃类水合物(甲烷水合物、乙烷水合物、乙烯水合物)导热的特性。结果显示化学性质相似、分子量相差不大的烃类形成的水合物,其导热具有相似的温度压力依赖关系和晶体结构相关关系。对于sⅠ型水合物,水分子对水合物导热的影响远远超过客体分子对导热的影响。水合物的分子量越大,水合物密度越大,热导率越大。水合物晶体越致密、晶格越规整,热导率越大。Equilibrium molecular dynamics simulations and the Green-Kubo method are used to the s I hydrates of methane, ethane and ethene to study their thermal conduction at temperature 263.15 K and pressure 3 MPa. Thermal conductivities and mean densities of the hydrates are obtained. Characteristics of thermal conduction in hydrates of hydrocarbon such as methane, ethane or ethene are studied for the effects of host and guest molecules and compactness and regularity of the crystal lattice on thermal conduction. The results show that thermal conduction is similar for the hydrocarbon hydrates that resembles chemically with indistinct difference in molecular weight. The thermal conduction of these hydrocarbon hydrates has similar temperature and pressure dependence and similar crystal structure correlation. The influence of water on thermal conductivity of s I gas hydrates goes far beyond the effect of guest molecules on it. With higher mean molecular weight in hydrates, higher densities are more conducive to enhance the thermal conductivity. More compact crystal lattices improve thermal conductivities. With more regular lattice structures, phonon mean free paths are longer, so that the thermal conductivity of hydrate increases.

关 键 词：水合物 热传导 分子模拟 Green-Kubo理论 晶体结构 分子量 规整程度 

分 类 号：O482.22[理学—固体物理]