关键词: 工程热物理, 诱导时间, 水合物晶体成核, 表面活性剂, 相平衡

Abstract: The influences of surfactants on induction time in thre
e types of solution with equal concentration of 1.0×10^-3 mol·L^-1
(T40,T40/T80 (1∶1),T40/T80 (4∶1)) were studied by means of visual hydrate experimental equipment and generalized induction time was measured by direct observation method.Then the experimental results were analyzed based on the mass transfer model,the model of hydrate crystal nucleus growth and the driving force equation of phase equilibrium.The results show that solubilization of surfactant makes gas molecules supersaturated which promotes the mass transfer from bulk phases to hydrate,and provides driving force for complexation of host molecules (water) and guest molecules in the reaction process of gas hydrate formation; the structural characteristics of surfactant and its aqueous solution state determine
itself to become micelle when CMC is exceeded which binds gas molecules and for
ms clusters with water molecule,the increase of clusters and decrease of unoccup
ied space in micelle increase the opportunities of clusters collision which prom
otes the crystal nucleus formation;solubilization of surfactant evidently decreases the chemical potential of solubilized mass, thus stabilizing the reaction system and promoting
the phase equilibrium of hydrate formation.It is found by comparisons that surf
actant T40 has notable effects on promoting hydrate nucleus formation and shortening induction time.

Key words: engineering thermophysics, induction time, hydrate nucleation, surfactant, phase equilibrium