La Cerva Mariagiorgia, Cipollina Andrea, Ciofalo Michele, Albeirutty Mohammed, Turkmen Nedim, Bouguecha Salah, Micale Giorgio
Dipartimento di Ingegneria, Università degli Studi di Palermo, viale delle Scienze ed.6, 90128 Palermo, Italy.
Center of Excellence in Desalination Technology, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
Membranes (Basel). 2019 Jul 25;9(8):91. doi: 10.3390/membranes9080091.
The membrane distillation (MD) process for water desalination is affected by temperature polarization, which reduces the driving force and the efficiency of the process. To counteract this phenomenon, spacer-filled channels are used, which enhance mixing and heat transfer but also cause higher pressure drops. Therefore, in the design of MD modules, the choice of the spacer is crucial for process efficiency. In the present work, different overlapped spacers are investigated by computational fluid dynamics (CFD) and results are compared with experiments carried out with thermochromic liquid crystals (TLC). Results are reported for different flow attack angles and for Reynolds numbers (Re) ranging from ~200 to ~800. A good qualitative agreement between simulations and experiments can be observed for the areal distribution of the normalized heat transfer coefficient. Trends of the average heat transfer coefficient are reported as functions of Re for the geometries investigated, thus providing the basis for CFD-based correlations to be used in higher-scale process models.
用于水脱盐的膜蒸馏（MD）过程受温度极化影响，这会降低该过程的驱动力和效率。为了抵消这种现象，使用了填充间隔物的通道，其增强了混合和传热，但也会导致更高的压降。因此，在MD模块的设计中，间隔物的选择对过程效率至关重要。在本工作中，通过计算流体动力学（CFD）研究了不同的重叠间隔物，并将结果与使用热致变色液晶（TLC）进行的实验进行了比较。报告了不同流动攻角和雷诺数（Re）范围从200到800的结果。对于归一化传热系数的面积分布，可以观察到模拟和实验之间有良好的定性一致性。报告了所研究几何形状的平均传热系数随Re的变化趋势，从而为在更高尺度过程模型中使用基于CFD的关联提供了基础。
