甲醇-乙醇混合工质振荡热管传热性能研究

Study on the heat transfer performance of the pulsating heat pipe using mixtures of methanol and ethanol as the working fluid

混合工质可为振荡热管带来独特的传热性能．比较甲醇、乙醇纯工质以及甲醇-乙醇混合工质振荡热管在不同充液率时的热阻随加热功率的变化情况，结果发现：在小充液率（45％）时甲醇-乙醇混合工质和乙醇振荡热管开始烧干时的加热功率高于甲醇工质振荡热管；在加热功率不是很大（低于65W）和大充液率（62％～90％）时，甲醇以及甲醇-乙醇混合工质振荡热管的传热性能优于乙醇振荡热管；在大加热功率（高于65W）和大充液率（62％～90％）时甲醇以及甲醇-乙醇混合工质振荡热管的热阻十分接近，均低于乙醇工质振荡热管的热阻，且热阻随着充液率的增加曲线变化越来越平缓．

For the Pulsating Heat Pipe （PHP）, using a mixed working medium may bring unique heat transfer performance. In this paper, the thermal-resistance dependence of the PHPs using methanol,ethanol and mixtures of methanol and ethanol on heating power was compared under different liquid ratios for the PHP. We concluded that the heating power for dryout onset of the PHPs using ethanol, and mixture of methanol and ethanol under small liquid ratios （45%） is obviously higher than that of the PHP using methanol; When the heating power is not very high （less than 65 W） and the liquid ratio is large （62% 90%）, the heat transfer performance of the PHPs using methanol, and mixture of methanol and ethanol is better than that of the PHP using ethanol; Under the condition of large heating power （higher than 65 W） and large liquid ratio （62% - 90%）, the thermal resistances of the PHPs using methanol, and mixture of methanol and ethanol have the approximate values and are lower than that of the PHP using ethanol. With increasing liquid ratio,their thermal resistances tend to be independent on the liquid ratio.