Research On Real Time Meteorological Conditions And Numerical Simulation Of Two Icing Processes

Using the real time observation data on500kV high voltage transmission lines in Hubei Province in February2008and January2009with MICAPS data and NCEP reanalysis data, the synoptic systems, moisture sources and meteorological condition during icing process are analyzed, it is also analyzed that which meteorological condition is the dominant factor.WRF has been used to simulte the icing process which occurred in February2008on zhangen2line, contrast with the measured data, and analyzed the trend of liquid water content. The main conclusions are as follow:(1) The deep pressure trough at500hPa and the center of the cold high at850hPa which is around Hubei Province have effect on ice thickness, and temperature is around-2℃, relative humidity is above90%and wind velocity is less than lm/s during two icing processes.(2) The main moisture sources of the two icing processes is the vapor that coming from South China Sea at850hPa with vapor from The India Peninsula and the Bay of Bengal at700hPa. The cold air coming from Mongolia and Russia which around to coastal areas on the east side cause more serious icing event.(3) According to the result of linear fit and grey relational analysis, the temperature of the air is the most important factor of these two icing processes in Hubei Province, at the beginning of icing, the correlation coefficients of air temperature and the wind speed are bigger, but at the end of the icing process, relative humidity take the dominant position.(4) Result from numerical simulation shows that the WRF model can provide a reference to the analysis of icing process. When the liquid water content is between0.3g·kg-1and0.4g·kg-1, ice accretion grows and remain, but if the liquid water content is below0.3g-kg·1, the ice accretion shed. According to the analysis of water mass concentration, the type of this icing processes is mixed icing.