关键词: 脉动热管, 充液率, 混合工质, 启动特性

Abstract: Start-up characteristics of pulsating heat pipe with different filling ratios were investigated under various starting power conditions using methanol,acetone and methanol/acetone volume ratio 1:1 as working fluids. Experimental results indicated that methanol/acetone mixture has a longer start-up time than acetone,but a shorter one than methanol at lower starting power. A proper increase of starting power can significantly shorten the start-up time of pulsating heat pipe,whereas it has a slight effect on the rise of starting temperature for acetone and methanol/acetone mixture. At higher starting power(60W),all the three working fluids had a temperature-jump at start-up,among which methanol/acetone mixture revealed the shortest start-up time. Moreover,the rise of starting temperature became longer with the increase of the starting power. The filling ratios evidently influence the activation method for pulsating heat pipe. The rise of starting temperature for acetone and methanol/acetone mixture gradually decreases with the increase of filling ratios. The two working fluids have a temperature-jump start-up at low and medium filling ratio(≤50%),but the start-up temperature transition tends to become smooth at high filling ratio of 80%.

Key words: pulsating heat pipe, filling ratio, mixed working fluids, start-up characteristic