Mi Menglong, Jiang Jian, Zhang Shulei, Dong Xinyu, Liu Lu
Department of Power Engineering, North China Electric Power University, Baoding 071003, China.
Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding 071003, China.
ACS Omega. 2022 Apr 12;7(16):14113-14120. doi: 10.1021/acsomega.2c00691. eCollection 2022 Apr 26.
A theoretical heat and mass transfer model of volatile liquid lens evaporation on the surface of an immiscible liquid substrate is established in toroidal coordinates. According to the coupled boundary conditions of heat and mass transfer at the lens surface as well as the interfacial cooling effect, the analytical solutions of the temperature field inside the lens and the vapor concentration field around the lens are derived for the first time. Compared with the isothermal model, the change of contact radius calculated by the present model agrees well with the experimental data, especially when the liquid substrate reaches a relatively high temperature. It also reveals that the temperature distribution inside the lens is not uniform, which is similar to the sessile droplet evaporation on a solid substrate surface. In addition, the excess temperature, heat flux, and evaporation flux of the lens-air interface increase monotonically from the lens center to the contact line. Finally, the influences of density ratio and evaporative cooling number on lens mass evaporation rate are analyzed, which shows that the lens mass evaporation rate decreases with increasing density ratio and evaporative cooling number.
在环形坐标系中建立了不混溶液体基底表面挥发性液体透镜蒸发的理论传热传质模型。根据透镜表面传热传质的耦合边界条件以及界面冷却效应，首次推导了透镜内部温度场和透镜周围蒸汽浓度场的解析解。与等温模型相比，本模型计算得到的接触半径变化与实验数据吻合良好，尤其是当液体基底达到较高温度时。研究还表明，透镜内部的温度分布不均匀，这与固体基底表面的 sessile 液滴蒸发情况类似。此外，透镜 - 空气界面的过余温度、热通量和蒸发通量从透镜中心到接触线单调增加。最后，分析了密度比和蒸发冷却数对透镜质量蒸发速率的影响，结果表明透镜质量蒸发速率随密度比和蒸发冷却数的增加而降低。
