平板热管测试系统加热面设计与优化

Design and optimization of heating surface of test system for flat heat pipe

为研究平板热管测试系统热源装置中电加热棒的位置分布对热源表面温度场分布、平板热管测试热阻的影响,设计了4种不同电加热棒位置的热源装置:电加热棒横向插入加热块中,且中心轴距加热块上表面的高度H分别为5,10,15,20 mm。研究结果表明:加热面存在一定的温差,且随加热功率的增大而增大。在辐射传热条件下,当加热功率为7 W时,高度H为15 mm的加热块,其加热面温差为2.05℃,表面热阻为0.13℃/W,电加热棒与加热面温差4.55℃;在强制空气冷却的条件下,当加热功率为60 W时,高度H为15 mm的加热块的表面热阻、平板热管测试热阻分别是高度H为5 mm的81.79%、91.23%,较其他3种热源装置,更符合平板热管性能测试要求。在验证模型正确的基础上,通过数值计算,进一步细化研究得出电加热棒的最佳位置为H=14 mm。

In order to study the influence of the location distribution of the electric heating rod on the distribution of temperature field on the heat source surface in the heat source device of flat heat pipe testing system and the testing thermal resistance of flat heat pipe,4 distinct kinds of heat source devices at different locations of electric heating rods were designed.The electric heating rod was broad wise inserted into the heating block,and the heights of the neutral axis from the upper surface of the heating block were 5,10,15,20 mm.The result shows that the heating surface exist certain difference in temperature which increases with the heating power increasing.When the heating power is 7 W,in the condition of radiative heat transfer,the height of the heating block is 15 mm,the difference in temperature of the heating wall is 2.05℃,the surface thermal resistance on the surface is 0.13℃/W,and the difference in temperature between the electrical heating rod and the heating wall is 4.55℃.When the heating power is 60 W,under forced air-cooling conditions,the heat resistance on the surface of 15 mm high heating block is 81.79% of that of 5 mm,and the testing thermal resistance of flat heat pipe in 15 mm high heating block is 91.23% of that in 5 mm.The 15 mm high heating block more conforms to the performance test requirements of flat heat pipe compared with the other three heat source devices.On the basis of verifying the correctness of the model,the optimum position of the electric heating rod is H=14 mm through numerical calculation and further detailed study.