标题： 相变传热中非凝结气体的界面温度和密度不连续性 显示英文标题

标题： Interfacial Temperature and Density Discontinuities for Phase-Change Heat Transfer With Non-condensable Gas

摘要： 在近期的前期工作中，作者推导了相变过程的界面质量通量和热量通量条件。质量通量条件与Schrage方程相同，但额外的热量通量表达式使得能够将界面与液相和汽相中的连续介质耦合，并计算界面处的温度和密度不连续性。然而，存在关于如何处理非冷凝气体存在下的相变传热的问题。在本工作中，作者表明可以使用同一组界面条件来考虑非冷凝气体的存在。尽管非冷凝气体的质量通量为零，但它们的存在会影响传热。对于蒸发，当非冷凝气体存在量较小时，界面处仍然存在温度和密度不连续性以及反向温度分布。然而，在冷凝过程中，当存在少量非冷凝气体时，不会发生温度反转，界面温度跳跃显著减小。当存在大量非冷凝气体时，例如在蒸发进入空气和从空气中冷凝的情况下，界面处的温度不连续性显著减小且不会发生温度反转。对于仅由湿度差驱动的蒸发，温度反转和不连续性仍然存在。本工作的结果将有助于在存在非冷凝气体的情况下相变过程的建模、空气中的蒸发冷却、空气间隙蒸馏、大气水收集以及其他应用。 显示英文摘要

摘要： In recent prior work, the author derived interfacial mass and heat flux conditions for phase-change processes. The mass flux condition is identical to the Schrage equation, but the additional heat flux expression enables one to couple the interface to the continua in both the liquid and the vapor phases and compute the interfacial temperature and density discontinuities. However, questions exist on how to treat phase change heat transfer in the presence of non-condensable gases. In this work, the author shows that the same set of interfacial conditions can be used to account for the presence of non-condensable gases. Although the mass flux of non-condensable gas is zero, their presence impacts the heat transfer. For evaporation, when the presence of the non-condensable gas is small, temperature and density discontinuities persist across the interface, as well as inverted temperature distributions. For condensation, however, no temperature inversion happens in the presence of a small amount of non-condensable gas and the interfacial temperature jump is significantly smaller. When a large amount of non-condensable gas is present, such as for evaporation into and condensation from air, the temperature discontinuities at the interface are significantly smaller and no temperature inversion happens. For evaporation driven purely by humidity difference, temperature inversion and discontinuity still exist. Results from this work will benefit the modeling of phase change processes in the presence of non-condensable gases, evaporative cooling in air, air-gap distillation, atmospheric water harvesting, and other applications.