基于有限元法的三相同壳结构GIS母线热分析

Thermal analysis of three-phase enclosed GIS bus bar based on finite-element method

气体绝缘开关设备(Gas-Insulated Switchgear,GIS)母线的载流能力与其运行温升密切相关.基于计算流体力学(computational fluid dynamics,CFD)原理对三相同壳结构GIS母线温度场进行分析.建立了母线涡流场、流体场以及温度场有限元耦合分析模型,并给出了模型边界条件.将涡流场计算结果作为流体-温度场计算的热源,为了提高计算的准确性,在进行温度场分析时考虑了流体物性参数随温度变化的关系,利用无量纲参数计算母线表面对流换热系数,最终得出母线流体场与温度场分布.通过计算结果与实验值的对比表明了模型的有效性.利用该模型分析了环境温度变化对GIS母线温度的影响,为GIS母线温度在线监测提供了理论依据.

The current carrying capacity of gas-insulated switchgear （GIS） bus bar is relative with the tem- perature rise during operation. On the basis of computational fluid dynamics （CFD）, the thermal field of three-phase enclosed GIS bus bar is analyzed. Finite element models coupling eddy current field, fluid field and thermal field are established, in which the boundary conditions are given. The calculation results of eddy current field analysis are used as the heat source for the fluid-thermal analysis. To improve the calcu- lation accuracy, the temperature dependent material properties are considered in the model. The distribu- tions of fluid and thermal fields are obtained. The results are compared with experimental data in the liter- ature and the model is proved to be efficient. The model proposed is applied to investigate the influence of changing ambient temperature on the temperature rise of GIS bus bar. The results provide theoretical ref- erence for the temperature on-line monitoring of GIS bus bar.