烃类水合物导热特性的分子动力学模拟

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。

Characteristic of thermal conduction in hydrocarbon hydrates using molecular dynamics method

Equilibrium molecular dynamics simulations and the Green-Kubo method are used to the sⅠ 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 sⅠ 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.