变电站绝缘子干冰清洗方形喷嘴流场模拟研究

喷嘴是干冰清洗系统中的关键部件之一,喷嘴结构及气流超音速自由喷流流场对清洗效果有很大的影响.通过Fluent软件,针对不同尺寸的喷嘴结构建立模型及进行仿真处理,模拟研究得到了方形喷嘴内部气体和唢出喷嘴气体的压力场及速度场.研究结果表明：气体射流在喷嘴出口处的压力远大于大气压,气体在喷嘴出口处产生了欠膨胀超音速气流,同时气体射流在周围环境中发生了激波现象.增加喷嘴尺寸,气体射流在环境中的速度衰减变缓,激波传输距离有所增加,从而使气体射流的稳定性降低.因此,在需要提高清洗效果、增加清洗面积时,可适当选用大尺寸的喷嘴.

Flow Field Simulation of Quadrate Dry-Ice Blasting Nozzle for Substation Insulators

Nozzles are one of the key parts of the dry-ice blasting system thanks to its significant influences of tile nozzle structm~ and the air supersonic free jet flow fields on the cleaning results. The modeling and simulation of the nozzles of different dimensions are conducted using Fluent software. Then the pressure and velocity fields of inner air flow and jet air flow of quadrate nozzles are obtained. The simulation results show that the air jet pressure at the nozzle outlet is much higher than the atmospheric pressure; a supersonic under-expanded jet is formed near the nozzle outlet accompanied by shock wave. Increasing the nozzle size can weaken the air jet velocity attenuation and extend the shock wave transmission distance, which may weaken the stability of the jet flow. Therefore larger scale nozzles should be selected properly to improve the cleaning effect and increase the cleaning area.