Numerical Research On Temperature Field Of Oil-Impressed Transformer Using Graphite Composite Materials

The power system includes four links:generation,transmission,distribution and consumption.Transformer is the main equipment in the transmission and distribution links.Its function is to convert the voltage of electric energy,making the electric energy more efficient and economic in the transmission and distribution process,In recent years,with the rapid development of national economy,the power consumption of residents and industry has been increasing,and the capacity and loss of transformer have been increasing.The problem of transformer overheating has also attracted more and more attention.Too high temperature leads to further increase of transformer loss,accelerated aging of insulation materials,brought safety risks and reduced power transmission efficiency,affecting the economy of power system operation.Because of its low cost and high heat dissipation power,the panel type radiator has become the mainstream radiator of oil immersed transformer.The number of the panel type radiators on the grid is very large.Therefore,it is of great significance to study how to strengthen the heat transfer capacity of the panel type radiator in many fields,such as saving resources,reducing the consumption of non-ferrous metals and reducing the floor area.The research on the heat dissipation of transformer has been listed in the 13th five year plan of State Grid Corporation of China.However,most of the current research is carried out from the aspects of heat dissipation environment and economic load,and the research results are limited by the actual engineering conditions,so it is difficult to widely promote and apply.This paper focuses on the heat exchange process between the panel type radiator and air,through improving the heat conductivity and emissivity of the anti-corrosion coating on the surface of the panel type radiator,enhancing the heat dissipation capacity of the panel type radiator,and achieving the goal of reducing the temperature rise of the transformer.First of all,this paper uses FLUENT software,following the principle of single variable,changing the thermal conductivity and emissivity of anti-corrosion coating to calculate the internal temperature field distribution of the chip radiator under the boundary conditions of maintaining the external air heat exchange conditions-and the.internal inlet oil speed.By comparing the results of heat dissipation between the control group and the basic reference group,the effectiveness and feasibility of the idea of enhancing the heat dissipation performance of chip radiator by improving the heat dissipation performance of anti-corrosion coating in this paper are verified.Secondly,the heat conduction mechanism of graphene composite was studied,and the method of adding high heat conduction graphene powder filler to improve the heat dissipation performance of the composite was determined.Thirdly,a series of graphene composites with different mass fractions were prepared.Then,the thermal resistance and emissivity of the coated graphene composites were measured by thermal resistance analyzer and infrared thermal imager,and the compounding ratio of graphene composites was optimized.Finally,experiments are carried out on the self-designed simulation experiment platform and the 10 kV distribution transformer temperature rise test platform to verify that the application of graphene composite material can effectively improve the cooling capacity of the transformer.