27.5kV GIS母线室三维温度场的数值计算

基于热传导微分方程、流体运动控制方程及辐射换热方程,建立了传导、对流和辐射换热相互耦合的数学模型,并采用壁函数方法处理固体与流体界面的对流换热问题,对27.5kV GIS(gas-insulated switchgear)开关柜母线室的三维温度场和气流场进行了数值计算与分析。仿真中采用了六面体网格剖分,通过有限容积法对方程进行离散求解,得到了母线室内的三维温度场与气流场的分布。计算结果表明,三工位隔离开关为温度最高部位,气体的对流使得母线室内温度趋于均匀并使载流回路的散热效果得到了加强。进行了相关的温升实验,温度的数值计算结果与实验结果吻合,表明了计算方法的正确性。

Three Dimensional Thermal Field Numerical Calculation of 27.5kV Gas-Insulated Switchgear Bus Bar’s Cabinet

Based on the heat conduction equation,fluid governing equation and radiation heat transfer equation;the coupled mathematical model of conduction,convection and radiation is established,the convection heat transfer problem between solid and fluid is solved by wall function;then the three dimensional thermal and fluid fields are calculated and analyzed.The hexahedral mesh is used in simulation;the differential equations are discretized and solved by the finite volume method.The 3D thermal field and fluid field distribution of 27.5kV GIS bus bar’s cabinet are shown.The result shows that the highest temperature part is at the three-position isolation switch,the temperature of the cabinet is made uniform and the heat transfer of the conductive loop is strengthened by the convection of the gas.The temperature rise test is done,and the computed temperature has good agreement with the results of temperature rise test,so it proves that this numerical method is reasonable.