Performance prediction and enhancement strategy of a new proton exchange membrane fuel cell-hydrophilic modified tubular still hybrid system

The abundant low-grade waste heat generation in proton exchange membrane fuel cell (PEMFC) not only leads to energy wasting but also degrades the cell durability. Herein, an innovative hybrid system model that integrates PEMFC with a hydrophilic modified tubular still (HMTS) is developed, aiming to remove and harness the waste heat for extra freshwater production. Based on thermodynamic and electrochemical theories and considering major irreversible losses within the system, the model is formulated to obtain the performance metrics. Computational results demonstrate that the hybrid system outperforms the independent PEMFC, exhibiting a 13.26 % increase in maximum output power density, as well as significant improvements in energy efficiency (6.49 %) and exergy efficiency (23.36 %). Exhaustive parametric studies show that raising the fuel cell's operation temperature and operation pressure and the wind velocity, or reducing the thermodynamic losses positively enhances the overall output performance. Nevertheless, enlarging the proton exchange membrane thickness, tube shell diameter, or length of the tube shell worsens the output performance. Local sensitivity analyses identify that the thickness of proton exchange membrane is the most sensitive factor affecting the output performance. These results are helpful for optimally designing and running a high-efficient system.