凝结蒸汽中加入添加剂对凝结换热影响研究

Theory and application of Marangoni condensation

研究当凝结蒸气中含有表面添加剂时单根管外的凝结换热。在对圆管外Marangon i凝结换热过程进行了理论分析的基础上,建立了含有凝结液膜的物理模型和基于边界层方程组的数学模型,应用相似理论进行了无量纲变换。计算结果表明,添加添加剂可以诱发界面流动,从而导致了气液界面处的液膜的不稳定,在气体凝结过程中产生了自发的扰动,加强了凝结换热。

Investigated the heat transfer process in the circular pipe when the vapour with the additive. Both physical model with the condensation fluid film and mathematical model based on the boundary layer equation were founded and then transformed to a non-dimensional form by applying the similarity theory. Result indicates that the effective additives trigger interfacial convection that leads to loss of hydrodynamic stability at the liquid/vapor interface and produce a spontaneous disturbance in the liquid condensate. As a result, condensation heat transfer is significantly increased.