闭式回路脉动热管在自然冷却下启动特性研究

Study on the Start-up Characteristics of Closed Loop Pulsating Heat Pipes under Natural Cooling

针对闭式脉动热管搭建试验平台,用紫铜管做试件,管内径2.7mm,全长1384mm,6弯头,丙酮为工质,采用底部电加热、上部自然冷却,研究不同加热功率下脉动热管启动特征及性能。结果表明,脉动热管存在三种启动方式:小功率下呈现间歇型启动特征但不稳定;中等功率下呈现温度突变型启动特征并可以稳定运行;高功率下呈现光滑连续启动特征并可以稳定运行。

Experiments are conducted on a close loop pulsating heat pipes ,which consists of long cooper tube with inner diameter 2.66 mm turned to 6 loops, filled with acetone, to analyze the start-up operational characteristics of the PHPS with different heating powers under the conditions of vertical bottom electrical heating and top natural cooling. Results show that the PHPs have three kinds of start-up modes： under lower heating power it starts up intermittently and unsteadily, under medium heating power it starts up with an apparent temperature overshoot then operates steadily; under higher heating power it starts up with a smooth temperature oscillation and operates steadily.