Hao Yanpeng

A comparative study of icing mechanism between soft rime and hard rime for the operating insulators

Transmission line icing involves drop diameter, wind speed, temperature and other parameters. In this paper, according to the China Southern Power Grid micro-meteorological, icing master image, and site acquisition droplet spectrum data, we use fluent to simulate the insulator soft rime, hard rime of super-cooled water drip ice process field, calculation of insulator umbrella skirt edge, on the surface, the number of droplets impact mandrel. The results show that, the hard rime icing the average temperature of -3.65 °C, humidity above 98%, the average days of rainfall 1.95mm; hard rime formed mainly in the rain and fog hard weather, precipitation are hard rime liquid water main source, the ice physical process for ice stem growth and wet growth alternately.

Research of morphology of soft rime on suspension insulator for transmission line

Icing process includes water droplets impacting, capturing and freezing. In this paper, we calculate the number of water droplets hit on different parts of insulator by Fluent, combine with micro-meteorological characteristics and icing graphs in transmission line to explain the physical processes of soft rime icing. The results show that: When soft rime icing, the water droplets mainly hit on edge of sheds, the average icing temperature is -2.83 °C, and frozen coefficient is greater than one. Granular ices on edge of sheds is the main performance of soft rime on insulator, besides, there are a small amount of granular ices on upper surface of sheds and insulator core too. Due to a small number of the total water droplets and a small impacting density, there tend to be more holes between the ice particles, so the granular ices are loosely structured and white, these phenomenon are identical to the graphs of soft rime on insulator for transmission line.