Study on the characteristics of natural gas hydrate crystal structures during decomposition process
Study on the characteristics of natural gas hydrate crystal structures during decomposition process
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DOI：
10.1016/j.fuel.2020.117537
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发表时间：
2020-07
期刊：
影响因子：
7.4
通讯作者：
Wuchang Wang;Xiaoyu Wang;Yuxing Li;Shuai Liu;Shupeng Yao;Song Guangchun
中科院分区：
文献类型：
--
作者：
Wuchang Wang;Xiaoyu Wang;Yuxing Li;Shuai Liu;Shupeng Yao;Song Guangchun
水合物分解是水合物形成过程中不可避免的现象，具有重要的研究意义。为了研究晶体分解过程，在高压可视高压釜中对天然气+纯水体系中水合物颗粒的形成和流动进行了实验研究。实验过程中，利用高速数码相机捕捉天然气水合物颗粒的微观形态和分解过程，利用高清相机在可视窗口捕捉天然气水合物的团聚状态，将宏观和微观现象有机地联系起来。通过对实验数据的分析，我们发现水合物颗粒的微观形貌大致可分为两类：平面片状颗粒和多面体固体颗粒。平面片状颗粒进一步细化为非主干雪花颗粒和主干生长的树枝状颗粒。当雪花颗粒开始分解时，它们的面积往往会减小，并且边缘呈圆形。树枝状粒子的分解时间较长，且体系中始终存在主干。在分解过程中，粒子数逐渐减少到零，但也会有轻微的增加。同时发现，较高的加热温度和初始压力会加剧颗粒数的波动。最后，根据高速数码相机等设备获得的水合物颗粒在分解过程中的微观变化，基于两类水合物颗粒独立的物理模型，建立了水合物颗粒分解的物理模型。
Hydrate decomposition is inevitable in the process of hydrate formation, and has an important research significance. In order to study the crystal decomposition process, the formation and flow of hydrate particles in natural gas + pure water system were experimentally studied in a high-pressure visual autoclave. During the experiments, the high-speed digital camera was used to capture the micro-morphology and decomposition process of gas hydrate particles, and the high definition camera was used to capture the agglomeration state of nature gas hydrate at the visual window to connect macro-and micro-phenomena organically. By analyzing the data obtained from experiments, we find that the micro-morphology of hydrate particles can be roughly divided into two categories: planar flake particles and polyhedral solid particles. The planar flake particles are further refined into non-trunk snowflake particles and dendritic particles with trunk growth. When snowflake particles begin to decompose, they tend to decrease in area and have rounded edges. The decomposition time of dendritic particles is longer, and there is always trunk in the system. During the decomposition process, the number of particles gradually decreases to zero, but there will be a slightly increase. Meanwhile, it is found that the higher heating temperature and initial pressure will aggravate the fluctuation of particle number. Finally, according to the microscopic changes of hydrate particles in the decomposition process obtained by high-speed digital camera and other equipment, and based on the independent physical models of two types of hydrate particles, the physical model of hydrate particles decomposition is established.