Water Management and its Mitigation Methods in Proton Exchange Membrane Fuel Cell.
The water balance in the fuel cell stack is one of the greatest challenges associated with PEMFCs. The water provided in the cathode product is not sufficient to keep the membrane hydrated, it is appropriate to use humidified reactant gases. This happens when the membrane gets dehydrated due to the anode’s high current density requirement. When the electro-osmotic drag is higher than the water back-diffusion, this problem arises, resulting in a greater flow of water from the anode to the cathode side. When thick polymer membranes are used, this issue is compounded because they need more water to stay hydrated. The anode’s humidification can be regulated by the humidification of hydrogen. Owing to the reaction and the electro-osmotic drag, it is difficult to maintain the water balance at the cathode because water accumulates excessively. The gas diffusion layers help to extract water from the electrodes, but the gradient of water concentration may depend on the porosity, thickness and hydrophobicity of the gas diffusion backers. The geometry of the flow channel affects the water content in the fuel cell as well. Flow velocity and rate of diffusion of the reactants to the electrode layers are influenced by the distance, length, depth and space between flow fields. It also determines how liquid water flows through the cell. The proposed study aims to optimise the performance and durability of PEMFC through optimising the above-mentioned parameters, more focus is to develop a model to predict the hydrophobicity requirement of GDL at different operating conditions.
Department of Mechanical Engineering, School of Engineering, Amritapuri
CFD
Assistant Professor,
Department of Mechanical Engineering,
School of Engineering,
Amrita Vishwa Vidyapeetham,
Amritapuri.
