Advanced Product Water Removal
Removing water, especially at zero gravity, has been a challenge since the first fuel cells were designed for the Gemini space program. Too much water in the cell and performance suffers; not enough water in the reactant gases results and individual cells dry out, risking cell failure. Most fuel cell systems rely on gravity and a large volume of air to move water away from the fuel cell membrane and out of each individual cell, exiting the fuel cell stack through the balance of plant.
When operating in an extreme environment like space a fuel cell design cannot rely on gravity and air to move water. Additionally, any reactant entrained in the fuel cell product water must be removed before the water can be used by the crew of a manned mission for drinking, as well as recycling the reactant back to the fuel cell. Traditional approaches to this problem involve centrifugal devices and ejectors designed to separate the two phase flow.
Infinity’s APWR development was started over a decade ago with NASA Glenn Research Center to find a solution to this problem. Drawing on the team’s Gemini fuel cell program experience, Infinity developed a porous structure based system in each individual cell of the fuel cell stack, eliminating the need for costly and often unreliable centrifugal systems, as well as power output limiting ejector schemes.