Abstract:

The heat pipe is a kind of heat transfer element that utilizes phase change heat transfer of working medium, with the advantages of small heat transfer temperature difference, fast thermal response speed, large heat exchange capacity and so on. In order to study the heat transfer performance of finned gravity heat pipe, the heat transfer characteristics of finned heat pipe and flat heat pipe (combination of aluminum-acetone) are investigated experimentally. The dynamic temperature responses of finned heat pipe and flat heat pipe are obtained and compared. The steady state temperature distributions along the length direction of finned heat pipe and flat heat pipe are measured under different heating power. Then the effective thermal conductivity of flat heat pipe is calculated with the temperature difference across the uniform temperature section. Comparison is made to the test results of aluminum. The results show that the gravity heat pipe has faster thermal response and better temperature uniformity along the pipe. With the increment of heating power, the effective thermal conductivity of gravity heat pipe increases at first and then decreases which is almost 84—258 times of aluminum. Compared with flat gravity heat pipe, the finned heat pipe has higher temperature uniformity and heat dissipation ability. Thus the finned gravity heat pipe has wide application prospect in architecture heating, vehicle battery heat dissipation and waste heat utilization.

Key words: finned gravity heat pipe, phase change, heat transfer, temperature uniformity, thermal conductivity

摘要：

热管是一种利用工质相变传热，具有传热温差小、热响应速度快、换热量大等优点的传热元件。为研究翅片重力热管的传热性能，实验测试了翅片重力热管与平板重力热管（铝-丙酮工质）的传热性能，比较了其瞬态热响应速率，获得了翅片与平板重力热管在蒸发段不同电功率稳定加热条件下表面温度沿高度方向的变化规律，计算了平板热管的等效热导率，并与铝板测量结果进行了对比。结果表明：重力热管传热速度快、表面均温效果好，热导率随功率的增大先升高后降低，整体上热导率高达纯铝的84~258倍，翅片热管相比于平板热管具有更好的均温性和散热效果，在建筑供暖、车载电池散热、余热利用等领域具有广泛的应用前景。

关键词: 翅片重力热管, 相变, 传热, 均温性, 热导率