功能涂层分割表面降液膜流动过程的CFD模拟

CFD Simulation of Influence of Coated Distribution on the Falling Liquid Film Flow Process

建立二维功能涂层分割表面流动模型,利用CFD方法研究了不同喷淋密度下功能涂层表面的降液膜流动过程。当喷淋密度小于最小喷淋密度时,壁面出现局部干壁并伴随液膜积聚和重新铺展现象产生。当喷淋密度大于最小喷淋密度时,含涂层壁面与不含涂层壁面对液膜的流动形态几乎无影响;但流动稳定之后,液膜内部的掺混加剧,可显著减薄传热边界层的厚度,对吸收器的传热传质性能起到影响。模拟结果与实验结果吻合良好,具有显著的实际意义。

Two-dimensional falling liquid film flow model of vertical coated distribution was built,and CFD method was used to study the falling liquid flow process on coated distribution under different spray density.When spray density was bigger than the minimum spray density,local dry spots were appeared on the wall along with the accumulation and re-spreading of the falling liquid film.On the contrary,there was no difference in flow form between the wall with and without coated region;but when the flow process was stable,the mixture inside the falling film was strengthened,which would reduce the thickness of the heat transfer boundary layer and promote the heat and mass transfer performance of the absorber.The simulation results were in good agreement with experimental phenomena of falling liquid film flow model of coated distribution wall,showed significant practical significance.