In order to improve the start-up and heat transfer performance of flat pulsating heat pipes with branch structures,the thermal characteristics of flat pulsating heat pipes with different branch lengths were studied.By designing and building a visual experimental platform,controlling parameters such as the type of working fluid,branch length,filling rate,heating power,and tilt angle,the start-up,heat transfer,and flow characteristics of the heat pipe are studied.The manifold and operating temperature curve of the working fluid are observed,and the heat transfer performance of the flat pulsating heat pipe is compared and analyzed.The experimental results showed that the starting mode of the flat pulsating heat pipe was progressive,and the working fluid evolved from bubbly flow to annular flow.Due to the existence of branching structure,the distribution of working fluid inside the tube is uniform,which shortens the start-up time of the heat pipe.The existence of branching structure greatly increases the heat transfer performance of the heat pipe,and under the optimal operating conditions(anhydrous ethanol,liquid filling rate of 50%,120 W,26 mm),the heat transfer performance is improved by 15.3%compared to the non branching heat pipe.
关键词
脉动热管/分支结构/均匀加热/渐进式启动/传热性能
Key words
pulsating heat pipe/branch structure/uniform heating/progressive startup/heat transfer performance
维普
万方数据