Abstract: The thermal resistance characteristics of ethanol-based binary mixture pulsating heat pipe was studied experimentally. The working fluids were ethanol mixed with water, acetone and methanol separately. Mixed ratio of volume was 2:1 and 4:1, heat power was from 10 W to 100 W, and filling ratio was 45%, 55%, 62%, 70% and 90%. Compared with the pure ethanol pulsating heat pipe at 45% filling ratio, mixed water with ethanol could delay the dry-out, and the thermal resistance of ethanol-water pulsating heat pipe was lower than that of pure water and ethanol. At 55% filling ratio, the thermal resistance of ethanol-acetone pulsating heat pipe is also lower, while at filling ratios of 62%, 70% and 90%, the thermal resistance of the binary mixture pulsating heat pipes was slightly higher than that of pure working fluids. The effect of the mixture on pulsating heat pipes is mainly related with the mixture properties, forces and momentum interchange among molecules, vapor-liquid phase equilibrium and phase change characteristics, and mass transfer resistance.

Key words: ethanol, mixture working fluid, pulsating heat pipe, heat transfer, phase equilibrium, vapor liquid equilibrium

摘要： 通过实验研究乙醇中分别加入少量水、丙酮、甲醇，体积比分别为2：1、4：1，加热功率从10 W到100 W，充液率为45%、55%、62%、70%、90%时振荡热管的热阻特性，并与纯乙醇工质振荡热管相比较。结果表明，45%充液率时，乙醇中加入水可以改善烧干，混合工质较乙醇、水纯工质振荡热管热阻小；55%充液率时，乙醇-丙酮混合工质较乙醇、丙酮纯工质振荡热管热阻小；大充液率62%～90%时，两组元乙醇基混合工质振荡热管传热性能略不如各纯工质振荡热管。混合工质对振荡热管的影响主要与物性、分子间相互作用、溶液汽液相平衡及相变特性、传质阻力有关。

关键词: 乙醇, 混合工质, 振荡热管, 传热, 相平衡, 汽液平衡