Temperature polarization is a crucial issue in the application of the membrane distillation technique, as it can significantly affect its entire performance. Experimental and numerical studies were conducted to decrease the temperature polarization in the feed and permeate channels by reducing the channel height. This is the first time that a study addresses the temperature polarization in membrane distillation by decreasing channel height. Furthermore, the feed inlet temperature and flow rate were studied by changing the channels’ height to obtain a comprehensive conclusion. Results showed that decreasing temperature polarization had a significant effect on the membrane surfaces’ temperatures, which in turn, significantly improved system productivity and thermal performance. In this study, the channels’ heights decreased from 2.5 mm to 1.5 mm; whereas, the feed inlet temperature and flow rate ranged from 58 °C to 78 °C and from 100 ml/min to 400 ml/min, respectively, and at constant feed salinity of 10 g/l. A 21% increase in the permeate flux was achieved when the channel height decreased from 2.5 mm to 1.5 mm at feed inlet temperature and flow rate of 78 °C and 100 ml/min, respectively. Furthermore, at the maximum considered flow rate of 400 ml/min this improvement enhanced both the thermal efficiency and specific energy consumption by 12.7% and 10%, respectively. The results also showed that feed inlet temperature had a significant impact on the whole system performance: productivity was more than doubled when feed inlet temperature was increased from 58 °C to 78 °C (at 1.5 mm channel height). However, increasing flow rate negatively affected both thermal efficiency and specific energy consumption even though it was proven to positively affect productivity. Finally, increasing the flow rate beyond 200 ml/min proved to be less significant with respect to permeate flux, thermal efficiency, and specific energy consumption.

温度极化是膜蒸馏技术应用中的一个关键问题，因为它会显着影响其整体性能。进行了实验和数值研究，以通过降低通道高度来降低进料和渗透通道中的温度极化。这是首次通过降低通道高度来解决膜蒸馏中的温度极化问题。此外，通过改变通道的高度来研究进料口温度和流量以获得综合结论。结果表明，降低温度极化对膜表面的温度有显着影响，进而显着提高了系统生产率和热性能。在这项研究中，通道的高度从 2.5 毫米降低到 1.5 毫米；而进料入口温度和流速分别为 58 °C 至 78 °C 和 100 ml/min 至 400 ml/min，且进料盐度恒定为 10 g/l。当进料口温度和流速分别为 78 °C 和 100 ml/min 时，通道高度从 2.5 mm 降低到 1.5 mm 时，渗透通量增加了 21%。此外，在考虑的最大流速为 400 毫升/分钟时，这种改进分别将热效率和比能耗提高了 12.7% 和 10%。结果还表明，进料口温度对整个系统性能有显着影响：当进料口温度从 58 °C 增加到 78 °C（通道高度为 1.5 毫米）时，生产率提高了一倍以上。然而，增加流速会对热效率和比能耗产生负面影响，尽管事实证明它会对生产力产生积极影响。最后，事实证明，将流速提高到 200 毫升/分钟以上对渗透通量、热效率和比能耗的影响不大。