| dc.description.abstract | An investigation was performed to demonstrate system design for the delivery of
water required for evaporative cooling of a proton exchange membrane fuel cell
(PEMFC). The water delivery system uses spray nozzles capable of injecting water
directly and uniformly to the nickel metal foam flow-field (element for distributing the
reactant gases over the surface of the electrodes) on the anode side from which water can
migrate to the cathode side of the cell via electroosmotic drag. For an effective overall
cooling, water distribution over the surface of the nickel foam has to be uniform to avoid
creation of hotspots within the cell. A prototype PEMFC structure was constructed
modeled after a 35 kW electrical output PEMFC stack. Water was sprayed on the nickel
metal foam flow-field using two types of nozzle spray, giving conical fog type flow and
flat fan type flow. A detailed investigation of the distribution pattern of water over the
surface of the nickel metal flow field was conducted. The motive behind the
investigation was to determine if design parameters such as type of water flow from
nozzles, vertical location of the water nozzles above the flowfield, area of the nozzles, or
operating variables such as reactant gas flow had any effect on water distribution over
the surface of the Ni-metal foam flow field. It was found that the design parameters
(types of flow, area and location of the nozzle) had a direct impact on the distribution of
water in the nickel metal foam. However, the operating variable, reactant gas flow,
showed no effect on the water distribution pattern in the Ni-foam. | en |
