Numerical and experimental study of a high permeable MOF/PVDF flat-sheet membrane module for enhanced evaporative cooling

The rapid growth in global data centre cooling demand highlights the need for energy- and water-efficient cooling systems to reduce energy use and carbon emissions. Membrane-based evaporative cooling systems enhance energy and water-use efficiency, resist cross-contamination, and mineral scaling than conventional evaporative cooling systems. Despite their promise, typical membrane systems often have relatively lower cooling capacity because of limited water vapour mass transport, impeding widespread adoption. To address the limitation, we developed a membrane module system fabricated with novel flat-sheet MOF-303 (metal-organic framework)/PVDF composite membranes. The permeability of composite membranes is 52.5 % higher than other commercial membranes. An experimental system was established to evaluate the module's cooling performance under various operating conditions. Additionally, a numerical model was developed to optimise the design of membrane module geometry, which was further validated with the experimental data. The results indicate the proposed module achieved exceptional high specific cooling capacity of 862 W/m2 and water use efficiency of 0.93. As a potential strategy for supplying cool water to liquid-cooled data centres, the proposed system demonstrated a 20 % higher wet-bulb cooling effectiveness than conventional closed recirculating cooling towers. The established numerical model produced good agreement with the experimental results, which was subsequently used to evaluate the effects of membrane properties, channel geometry and operating conditions of membrane module on its overall performance. Favourable membrane properties, channel geometry and operating parameters are recommended to enhance its cooling performance.