油浸式变压器导油板对油流特性与温度分布的影响

Oil-guiding Plate Effect on the Oil Flow Characteristics and Temperature Distribution of Oil-immersed Transformer

变压器的绕组和绝缘油之间散热不均导致绕组局部热点温度过高,影响绝缘材料的绝缘特性。为研究油道和导油板对变压器油的流速、流向以及热点温度的影响,首先对变压器流体域、固体域以及流-固交界面上的传热模型进行分析,确定了流-固界面的传热数学模型。基于此,构建并求解了油浸式变压器数值仿真模型,利用变压器温升试验结果验证了数值模型的准确性。最后,在数值模型中研究了两种横向导油板对变压器油的流场和温度分布的影响。研究表明:基于流-固耦合特性构建的数值模型温度偏差小于1℃时,横向挡油板使水平油流平均油速和峰值流速分别提高1.4倍和2.3倍,提高了流-固耦合区域的换热效率,绕组平均温度和热点温度下降3℃以上,为变压器绕组散热分析与结构设计提供了新方法。

The nonuniformity of heat dissipation between transformer winding and insulation oil can cause higher local hot-spot temperature of the winding,which affects insulation characteristics of the insulation materials.For purpose of investigating both oil channels and oil guide plates’effect on the transformer oil’s velocity,flow direction and hot spot temperature,analyzing heat transfer models of the transformer fluid domain,solid domain and the fluid-solid intersection interface was implemented and the mathematical model of the heat transfer at the fluid-solid interface was determined.Based on this,the numerical simulation model of the oil-immersed transformer was constructed and solved,and having transformer temperature rise test results based to verify accuracy of the numerical model.Finally,in a numerical model,the effects of two transverse oil-guiding plates on the transformer oil’s flow field and temperature distribution were studied.The results show that,the numerical model’s deviation based on the fluid-structure interaction characteristics is less than 1℃,and the transverse oil deflector increases average oil velocity and peak flow velocity by 1.4 times and 2.3 times,respectively,and the heat transfer efficiency in fluid-structure interaction area is improved.The average temperature and hot-spot temperature of the winding are decreased by more than 3℃,which provides a new method for analysis and design of transformer winding heat dissipation.