Quasi-passive variable pressure regenerative fuel cell system

DETAILED DESCRIPTION Conventional passive, variable pressure, regenerative fuel cell systems utilize mechanical valves, pressure regulators, feed pumps, and recirculation pumps.
Many systems also include active heating and cooling control loops in both the gaseous hydrogen and oxygen storage tanks to feed water to the anode side of the fuel cell during electrical power production (to prevent fuel cell anode drying), and for draining water from the cathode side of the electrolyzer during electrical recharging operations.
A quasi-passive regenerative fuel cell system in accordance with the invention utilizes hydrogen that is stored in a metal hydride form.
Advantageously, this embodiment reduces the system's operating pressures from roughly 21 MPa (3,000 psia) to roughly 2.
1 MPa (300 psia), when fully charged, and eliminates the need for gaseous oxygen storage altogether.
All oxygen consumed by the fuel cell system can be extracted directly from the surrounding air.
All oxygen produced by the electrolyzer is, in turn, vented back into the atmosphere.
Another distinctive aspect of the invention is its use of an anode wick to substantially reduce the probability of drying a fuel cell's anode membrane surface.
An anode wick, in accordance with the invention, establishes a physical connection between a fuel cell's anode membrane surface and a liquid water reservoir.
Wicking action substantially ensures the cell's anode surface is continually bathed in water.
Two mechanical check valves are incorporated to effectively prevent mixing of gaseous hydrogen and oxygen gases in the event the fuel cell system's water tanks become over pressurized.