Rayleigh convection is an interfacial transport phenomenon in the CO₂ capture and storage processes. In the present paper, we proposed a mesoscale model to capture the convection structure caused by Rayleigh convection in a 20 mm × 10 mm CO₂ absorption cell with low mesh density. To close this mesoscale model, we analyzed the relationship between entropy generation caused by mass transfer and viscous dissipation, and raised a criterion. This criterion was also verified by a PIV/LIF quantitative experiment in CO₂ absorption cell with $Ra=1.15\sim 2.3\times {10}^7$. The proposed mesoscale method can prediction the concentration and velocity distributions of Rayleigh convection effectively. The relative error of total mass transfer flux can be decreased from 43% to 6.3%. The idea of this mesoscale method is promising for solving complicated transport problem that is difficult to find the conservation model.

瑞利对流是CO ₂捕获和储存过程中的界面传输现象。在本文中，我们提出了一个中尺度模型来捕获由20毫米×10毫米CO _2的低网格密度吸收池中的瑞利对流引起的对流结构。为了关闭该中尺度模型，我们分析了由传质引起的熵产生与粘性耗散之间的关系，并提出了一个标准。该标准还通过PIV / LIF定量实验在CO ₂吸收池中进行了验证，$\mathrm{[R}\mathrm{一种}=1.15〜2.3\times {10}^7$。提出的中尺度方法可以有效地预测瑞利对流的浓度和速度分布。总传质通量的相对误差可以从43％降低到6.3％。这种中尺度方法的思想有望解决难以找到保护模型的复杂运输问题。