载气蒸发的传热性能

Heat Transfer Characteristic of Gas Carrying Ewaporation

本研究以空气-水为物系,在减压条件下,于Φ22×3.5 mm,长1500 mm的垂直管中进行了载气蒸发传热实验。研究了平均传热膜系数和局部传热膜系数随液速、载气流量及操作温度的变化规律,并分析了载气强化沸腾传热的机理。在此基础上获得了载气蒸发传热膜系数的关联式。

'Gas Carrying Evaporation' is a process in which anf inert gas is introduced into the boiling liquid, and the liquid evaports on gas-liquid phase surface. The experiment of GCE for air-water system was carried out in a vertical tube having φ22×3.5mm in diameter and 1500 mm in length under vacuum condition. In experiment average heat transfer coefficients and local heat transfer coefficients were investigated in various liquid velocities, carrying gas flow rates and operating temperatures. Furthermore, the enhancing mechanism of boiling heat transfer for GCE was analysed in detail. On this basis, a correlation of heat transfer coefficient for GCE was obtained using the concept of additive contribution to total heat transfer and nonliear regression of the experiment data.