甲醇、丙酮及其二元混合工质脉动热管的启动特性

以甲醇、丙酮以及二者体积比1：1混合组成的甲醇/丙酮混合液为工质，对脉动热管在不同加热功率和充液率下的启动特性进行了实验研究，结果表明：在低加热功率下时，甲醇/丙酮混合工质的启动时间比丙酮长，比甲醇短，适当增加启动功率可以明显缩短脉动热管的启动时间，但是对丙酮及混合工质的启动温升影响不大；在60W高加热功率下时，3种工质的启动方式均为温度突变型，其中混合工质的启动时间最短，并且增加启动功率可以明显地提高混合工质脉动热管的启动温升；充液率对脉动热管的启动方式影响较为明显，丙酮和混合工质的启动温升均随着充液率的增加而逐渐减少，在中低充液率（≤50%）下，二者属于温度突变型启动，而在80%高充液率下，其启动方式变为温度平稳过渡型启动。

Experimental study on the start-up characteristic of pulsating heat pipe with methanol/acetone and binary mixed working fluids

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%.