Open And Dust Weather Simulation Experiment Platform For High Altitude UHV Transmission Lines

Due to the advantages of high transmission capacity and energy consumption,UHV transmission has broad prospects for development.However,the high altitude and dust environment in northwest China will affect the corona characteristics of UHV transmission lines,thus affecting the safe and orderly operation of power grid.Therefore,the development of sand and dust weather simulation platform can lay the material foundation for the experimental study of corona characteristics of transmission lines.In this paper,the basic theory of gas-solid two-phase flow is expounded.According to the corona experiment,the experimental parameters are determined.On this basis,three different kinds of dust weather simulation experiment platforms are designed,which are based on free falling sand,swirling and class flat throw diffusion.Combination of theoretical analysis and numerical simulation,particle diffusion regions of these three schemes are compared and analyzed with the change of particle diameter and wind speed,so as to find out the solution satisfying the requirement of experiment and convenience of controlling.The experimental platform of the swirl diffusion scheme is optimized by shortening the length of particle diffusion tube and reducing the pressure loss of the platform.And the particle diffusion of the optimized platform under different sedimentation rates,particle diameters and wind speeds are researched to obtain characteristics of dust concentration in the experimental area.The fan and feeder,as well as the controlling,measures and supporting equipment are selected to promote and improve its engineering application in the optimization platform.And the feed characteristics of the feeder are discussed experimentally.Results show that: 1)The experimental platform of the swirling diffusion scheme not only meets the requirements of experimental but also is controlled conveniently;2)Optimized parameters of the experimental platform are as follows: length of up and down straight pipe is 2m,angle of front and back deflector is 30?,axial distance of feeding pipe to front stage deflector is 0.5m and feeding port is located at the duct axis.Compared with results before the optimization,pressure loss coefficient is reduced by 0.25;3)The optimized experimental platform can satisfy the dust coverage of 3?3m2 in the experiment area where it is 4m away from the duct and the elevation is 6.72 m.Dust concentration can be controlled precisely under the diverse conditions.4)In the case of particles supplying rate,wind speed and silt mean size are(0.005 ~ 0.03)kg/s,(6 ~ 9)m/s and(0.125 and 0.25)mm respectively.Dust concentration in the experimental area of the optimized experimental platform increases firstly then decreases with the increase of wind speed and the corresponding wind speeds at inflection points with particle diameters being 0.125 mm and 0.25 mm are 7m/s and 8 m/s separately.The increase of dust concentration increases with the growing of particles supplying rate;5)Relation of feeder feed rate and the feeder frequency is linear basically.