Abstract A two-equation continuum model is developed to simulate the mass transfer in drying porous media. The main goal is to capture the so called non-equilibrium effect. To this end, we operate in a regime where the liquid phase is immobile so that non-equilibrium mass exchange between liquid and vapor phase dominates. The formulation of the model relies on an upscaling technique. This notably permits to formulate the non-local equilibrium phase change term on a firmer basis. The upscaling also indicates that there is no reason to consider an enhancement factor in the vapor diffusion model. The macroscopic model parameters are determined from pore network drying simulations. The same simulations are also used as a reference to compare with the predictions of the non-local equilibrium continuum model. The solution of the two-equation continuum model proves that this model simulates the non-local equilibrium effect with reasonable accuracy. Also, the simulations indicate that the non-local equilibrium effect is especially significant at the porous medium surface.

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部分饱和干燥多孔介质的非局部平衡连续介质模型：与孔隙网络模拟的比较

摘要 建立了两方程连续介质模型来模拟干燥多孔介质中的传质过程。主要目标是捕捉所谓的非均衡效应。为此，我们在液相固定的状态下操作，以便液相和气相之间的非平衡质量交换占主导地位。模型的制定依赖于升级技术。这特别允许在更牢固的基础上制定非局部平衡相变项。放大还表明没有理由在蒸汽扩散模型中考虑增强因子。宏观模型参数由孔隙网络干燥模拟确定。相同的模拟也用作参考以与非局部平衡连续体模型的预测进行比较。二方程连续体模型的求解证明该模型以合理的精度模拟了非局部均衡效应。此外，模拟表明非局部平衡效应在多孔介质表面尤为显着。