浇注线圈径向导热系数的实验测试和数值模拟

Experimental Test and Numerical Simulation on the Radial Heat Conductivity of Casting Winding

基于稳态传热法基本原理,采用自制实验装置对模拟线圈试样的径向导热系数进行了实验测定,按照热力学平衡方程推算线圈的导热系数。采用三维计算流体动力学软件FLOW-3D建立了全尺寸线圈的分析模型,考虑导热、对流和辐射3种传热方式以及密度扩散方程,计算了导热系数分别为λ=0.25 W/m.K、λ=0.3 W/m.K、λ=0.35 W/m.K和λ=0.4 W/m.K4种工况,与实验测得的线圈内外壁温度分布进行对比,结果表明,λ=0.3 W/m.K这种工况更接近实验测试结果,为变压器温度场计算提供了真实的材料参数。

Based on the steady heat transfer theory,the radial heat conductivity of simulation winding specimens was measured by experimental apparatus.Heat conductivity was calculated using thermodynamic equilibrium equation.In addition,the analysis model of full-scale winding was established by using 3D computational fluid dynamics code FLOW-3D.Considering three heat transfer ways of conduction,natural convection,radiation and density diffusion equation,the four conditions with heat conductivity（λ） being λ=0.25 W/m·K,λ=0.3 W/m·K,λ=0.35 W/m·K and λ=0.4 W/m·K were analyzed respectively,and then compared with the tested temperature distribution of internal and external surfaces of windings.Simulation results indicate that the working condition of λ=0.3 W/m·K is close to the experimental results,which provides real material parameters for calculation of transformer temperature field.