垂直管内载气强化二元混合物沸腾传热

Enhancement of Boiling Heat Transfer for Binary Mixture in Vertical Tube

在垂直管内二元混合物的流动沸腾传热过程中 ,引入空气作为载气 ,改变其传热机理从而强化其传热性能。研究不同质量分数的乙醇水溶液 ,在不同操作压力、液体流速和载气流速条件下 ,其平均传热膜系数和壁面过热度的变化规律。分析讨论了载气引入强化沸腾传热各因素的影响并对实验数据进行了关联计算。结果表明 ,关联式能较好的反映各因素的影响 ,其偏差在 -2 3 %～ +2 0 %之间 ,平均偏差为 8.3 1

The experimental apparatus was set up to study the boiling heat transfer for binary mixture by introducing air into the system. The ethanol aqueous solrtion with different concentration was used to conduct the experiment.The results showed that the average heat transfer coefficient increased with increasing the air velocity,but decreased with increasing the ethanol concentrations and the vacuum. The correlation was given by dimensional analysis method with consideration of the effect of pressure,liquid and gas velocity. The calcrlated results showed a better agreement with the experimental data.