Simulation Analysis And Experimental Study Of RTV Coatings Sprayed On Surface Of Porcelain Insulators

At present,outdoor porcelain insulators usually need to be coated with room temperature vulcanized silicone rubber(RTV)coating to ensure their reliable insulation performance.The spraying of insulating coatings is a key technology in power maintenance.The setting of process parameters in the spraying process affects the quality of coatings.Through numerical simulation analysis of nozzle atomization flow field and RTV coating test of prototype spraying,the process parameter design of RTV spraying process for porcelain insulators with open-close spraying device is determined,and the coating quality of RTV coating for porcelain insulators installed outdoors is improved.Firstly,according to the structure of ceramic insulator umbrella skirt and the characteristics of outdoor spraying,the overall design scheme of open-close spraying device is determined,which can be adjusted in a certain angle and diameter range to meet the spraying requirements of different ceramic insulators.Based on the characteristics of RTV coating,the influence factors of spraying process parameters on coating thickness and coating quality are analyzed,which can be used to guide the later numerical simulation and the formulation of actual spraying test plan.Secondly,according to the basic theory of Fluent fluid dynamics simulation software,the numerical simulation analysis of the gas flow field outside the nozzle is carried out,and a continuous phase simulation calculation model is established.By setting the structural parameters of the upper hood of the nozzle,such as the pressure of the fan control hole,the spraying distance and the diameter of the central atomization hole,the influence of different operating parameters on the atomization effect of the nozzle is analyzed.Then,according to Lagrange's theorem of computational fluid dynamics and spray liquid atomization mechanism,the simulation model of discrete phase atomization in nozzle external flow field was established.The influence factors of gas-liquid volume ratio on spray atomization effect were determined by setting the parameters of gas-liquid volume ratio in the process of atomization,and the simulation results were analyzed.Finally,according to the results of simulation analysis and the design of influencing parameters,a set of test prototype suitable for experimental analysis is assembled,and the test prototype is debugged,and the RTV coating field spraying test is carried out by setting parameters.The results of test parameters are basically in agreement with the simulation results,which verifies the validity of the simulation results.According to the experimental parameters,RTV spraying process parameters of ceramic insulators are set.The actual spraying test results of ceramic insulators show that the coating thickness is uniform,the surface quality is good,there is no accumulation of tumors or hanging phenomenon,and the final coating thickness is in the range of 0.4-0.6 mm after curing in greenhouse,which meets the relevant technical requirements of the power industry.This paper is devoted to the improvement of RTV spraying device for ceramic insulators and the related theoretical and Experimental Research on spraying atomization parameter setting.It lays a foundation for further improving RTV spraying method and improving coating quality.