一系列实验在热输送的搏动的关上的循环(PHP ) 的三种类型上被执行,打算调查流动模式的各种各样的类型,并且开发为 PHP 的一些改进配置。光可视化结果显示那可能在那里存在三个流动模式,即水泡液体蛞蝓流动,半环形的流动和环形的流动,相应于不同工作条件。为给定的几何学并且一足够充满比率, PHP 为流动模式有自动调节的特征(从蛞蝓流动到半环形然后到环形的流动) 到会,增加的要求加热输入。二种特殊配置,有或者改变隧道直径的,与更厚的试管的一节装备的其它,被发现在建立并且维持工作液体的可靠循环有益。PHP 的热表演在工作条件的一个范围上被检验。与一致直径与正常 PHP 作比较,改进 PHP 的任何一个展出了更高热的性能。
A series of experiments were performed on three types of closed loop pulsating heat pipes (PHPs), intending to investigate various kinds of flow patterns, and to develop some improved configurations for the PHPs. Optical visualization results indicated that there might exist three flow patterns, i.e. bubble-liquid slug flow, semi-annular flow and annular flow, corresponding to different working conditions. For a given geometry and an adequate fill ratio, the PHPs had the self-adjusting characteristic for the flow patterns (from slug flow to semi-annular and then to annular flow) to meet the demands of the increasing heat input. Two special configurations, one with alternately varying channel diameter, the other equipped with one section of thicker tube, were found to be advantageous in establishing and maintaining reliable circulation of the working fluid. The thermal performance of the PHPs was examined over a range of working conditions. Comparing with the normal PHP with uniform diameter, either of the improved PHPs exhibited higher thermal performance.