Reactant Humidification Using Water Atomization and Porous Water Transport Plates in a PEM Fuel Cell
Publication Date: 2004-May-26
The IP.com Prior Art Database
Reactant Pre-Humidification Using Water Atomization and Porous Water Transport Plates in a PEM Fuel Cell, decreases flooding, and increases membrane exposure to water.
USING WATER ATOMIZATION AND POROUS WATER TRANSPORT PLATES
IN A PEM FUEL CELL
In a PEM fuel cell, dry reactant gases can dehydrate the membrane and lead to failure of the membrane. Some PEM fuel cells use water transport plates (“WTPs”) to humidify the reactants. However, the WTP does not always fully humidify the reactants before they reach the active area and are exposed to the membrane.
As a solution to this problem, the reactants are pre-humidified by atomizing water droplets into the reactant stream. The fine water droplets created in the atomization process increases the contact area for humidification of the reactants, and thus the reactants can reach full humidification before entering the active area. This reduces the risk of membrane failure due to dehydration. Any excess water present in the reactant stream can be absorbed into the WTP.
The atomization of the water could be achieved by several methods, such as nozzles, ultrasonication, etc. The water injection ports could be incorporated directly into the manifolds.
Humidification using water atomization is not novel. However, using this technique in a fuel cell system that has solid separator plates instead of WTPs increases the likelihood of flooding within the cell, since any excess water would need to be removed by entrainment or by shear-driven flow. In a cell with water transport plates, the excess water is simply absorbed into the water transport plate and into the coola...