Study on the natural air cooling of electronic equipment casings: Effects of the outlet vent and the power heater locations on the cooling capability
Study on the natural air cooling of electronic equipment casings: Effects of the outlet vent and the power heater locations on the cooling capability
复制标题
电子设备外壳自然风冷研究：出风口和功率加热器位置对冷却能力的影响
DOI：
10.1243/095765002320183586
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Y. Kitamura
中科院分区：
文献类型：
--
作者：
M. Ishizuka;G. Peng;Y. Kitamura
本文研究电子设备机壳的自然冷却问题。以实际自然风冷电子设备机壳为模型，通过实验研究了出口排气口的大小、位置以及出口排气口位置与动力加热器位置的相对距离对流动阻力的影响。结果表明，壳体内的平均温升随加热器输入功率的增大而增大，但在对数坐标下随通风孔隙度系数的增大而线性减小。当加热器接近出口排气口时，温升在对数范围内呈线性增加。通过定义一个新的无量纲参数--当量雷诺数，发现流动阻力系数与当量雷诺数之间存在密切的对数线性相关关系，K=kxχ−1.5。与实验结果吻合较好，验证了该方法的有效性。结果表明，在实际工程设计中，烟囱出风口到散热单元的相对距离可以作为烟囱高度。虽然还需要更详细的验证，但流动阻力系数、雷诺数和孔隙率系数之间的关系已经为自然冷却电子外壳的设计应用提供了有用的关联式。
Abstract This paper is concerned with the natural cooling of electronic equipment casings. Effects of the size and the location of the outlet vent as well as the relative distance from the outlet vent location to the power heater position on the flow resistance have been investigated experimentally by using a simple model casing simulated for practical natural air cooled electronic equipment casings. The result shows that the mean temperature rise inside the casing increases with increase in the heater input power, but decreases linearly with increase in the vent porosity coefficient in logarithmic coordinates. As the heater approaches the outlet vent, the temperature rise increases linearly in the logarithmic scale. By defining a new dimensionless parameter called the equivalent Reynolds number, involving the Reynolds number and the porosity coefficient, the flow resistance coefficient is found to have a close logarithmic linear correlation, K = kxχ−1.5, with the equivalent Reynolds number. Its validation has been proved by the good agreement with experimental results. The result indicates that the relative distance from the outlet vent to the heat dissipation unit can be considered as a chimney height in the practical engineering design. Although further more detailed validations are needed, a useful correlation between the flow resistance coefficient, the Reynolds number and the porosity coefficient has been presented for the design application of natural cooling electronic casings.