HCFC-141b制冷剂气体水合物生长过程的形态

HCFC-141b REFRIGERANT GAS HYDRATE FORMATION MORPHOLOGY

通过实验观测了HCFC - 141b制冷剂气体水合物的生成过程 ,认为水相和制冷剂相在过冷的条件下在界面上局部成核 ,成核扩展至两相接触的整个界面 ,水合物的进一步生成是由于制冷剂相通过水合物层扩散到水相中形成的 .利用显微实验的生成图像计算了水合物晶体的生长速率 ,并与外冷实验中的晶体生长速率比较 ,认为扰动增大了制冷剂相和水相的两相相界面的接触维数 .

Macroscopic and microscopic morphology of the formation of HCFC-141b gas hydrate were obtained by a set of low temperature experiments. The macroscopic morphology was recorded by a digital video camera, and the microscopic morphology was recorded by a microscope with a camera, magnified by 200 times. The test results indicated that the nucleation of gas hydrate had started at the two interfaces: between liquid water and liquid refrigerant or between liquid water and vapor refrigerant. The nucleation then gradually expanded to the whole boundary and formed a layer of hydrate. After that, refrigerant liquid diffused continuously into water through hydrate layer and formed new hydrate. The growth rate of gas hydrate was obtained from the microscopic photos and was compared with that in the former extermal cooling experiment. It was shown that disturbances could enhance the contact dimension between refrigerant and water phases.