A novel three-dimensional CFD simulation of H 2 gas permeation through dense palladium (Pd) membrane was developed. Due to discontinuity of flow in a membrane, usually, gas diffusion process is simulated by introducing source and sink terms. In a novel approach, an analogy between heat and mass transfer is considered. The most important advantage of this approach is that there is no need to define sink and source terms, and the membrane thickness is considered as a solution domain without separating the geometry adjacent to the membrane. Also, it allows the modeling of multilayer membranes with different mechanisms of diffusion, separately. The effect of membrane geometry on the hydrogen separation was investigated using the straight and helical modules by defining user-defined function (UDF) and user-defined scalars (UDS). The results showed an average flux and H 2 recovery enhancement of 20% and 13% for helical configuration, respectively. The influence of the feed gas and sweep gas flow rates, helix pitch, coil diameter, pressure difference, and module temperature on hydrogen separation was also investigated. The proposed simulation model was validated using the experimental data. The results indicated that this method has a maximum error of about 10% for H 2 flux.

中文翻译：

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Pd 基螺旋和直膜管分离 H2 的新型 CFD 模拟

开发了一种新型的 H 2 气体通过致密钯 (Pd) 膜渗透的三维 CFD 模拟。由于膜中流动的不连续性，通常通过引入源和汇项来模拟气体扩散过程。在一种新颖的方法中，考虑了传热和传质之间的类比。这种方法最重要的优点是不需要定义汇和源项，并且膜厚度被认为是一个解决方案域，而不会将与膜相邻的几何体分开。此外，它还允许分别对具有不同扩散机制的多层膜进行建模。通过定义用户定义函数 (UDF) 和用户定义标量 (UDS)，使用直模块和螺旋模块研究了膜几何形状对氢分离的影响。结果显示螺旋构型的平均通量和H 2 回收率分别提高了20%和13%。还研究了进料气和吹扫气流速、螺距、盘管直径、压差和模块温度对氢气分离的影响。使用实验数据验证了所提出的仿真模型。结果表明，该方法对于H 2 通量的最大误差约为10%。