摘要:
A fuel cell stack that includes an actuating device or devices for selectively providing interdigitated reactant gas flow and straight reactant gas flow through reactant gas flow channels to reduce water accumulation in the diffusing media layers of the stack. In one embodiment, the fuel cell stack employs internal actuators that selectively close the inlet end of every other flow channel and the outlet end of every other opposite flow channel to provide the interdigitated flow. In another embodiment, the interdigitated flow is provided by external actuation where two inlet manifolds and two outlet manifolds are provided. One input manifold is closed to close the input ends of every other flow channel and one outlet manifold is closed to close the output ends of every other opposite flow channel.
摘要:
A fuel cell system with a proton exchange membrane. There is a cathode catalyst layer overlying the first face of the proton exchange membrane, and a cathode diffusion layer overlying the cathode catalyst layer. There is an anode catalyst layer overlying the second face of the proton exchange membrane, and an anode diffusion layer overlying the anode catalyst layer. The cathode diffusion layer has a water vapor permeance of less than about 3×10−4 g/(Pa s m2) at 80° C. and 1 atmosphere. The invention also relates to cathode diffusion layers for fuel cell systems.
摘要:
An electrically conductive fluid distribution element for use in a fuel cell having a conductive metal substrate and a layer of conductive non-metallic porous media. The conductive non-metallic porous media has an electrically conductive metal deposited along a surface in one or more metallized regions. The metallized regions improve electrical conductance at contact regions between the metal substrate and the fluid distribution media.
摘要:
A fuel cell assembly is disclosed, the fuel cell assembly including a pair of terminal plates, one terminal plate disposed at each end of the fuel cell assembly, a fuel cell disposed between a pair of end fuel cells and the terminal plates, and a thermally insulating, electrically conductive layer formed between the fuel cell and one of the terminal plates adapted to mitigate thermal losses from the end plate, and fluid condensation and ice formation in an end fuel cell. The end fuel cells of the fuel cell assembly have a membrane and/or a cathode having a thickness greater than an average thickness of a membrane and/or a cathode disposed in the fuel cell that may be used in conjunction with, or instead of, the insulating layer to further mitigate thermal losses from the end plate, and fluid condensation and ice formation in the end fuel cells.
摘要:
This invention provides a method of transmitting and receiving packets containing data and positional information for a plurality of devices in a radio frequency network in combination with a global positioning system. The periodic position coordinates of each said device are determined using the global positioning system. The position coordinates are transmitted from each device at staggered points in time that are randomized, and the randomizing operation is performed in discrete steps, wherein the time period of each discrete step is of adequate duration for one device to transmit a positional update. A positional update table and proximity table is created and maintained for each device, and these tables are transmitted to every other device in the network at periodic intervals.
摘要:
A fuel cell system with a proton exchange membrane. There is a cathode catalyst layer overlying the first face of the proton exchange membrane, and a cathode diffusion layer overlying the cathode catalyst layer. There is an anode catalyst layer overlying the second face of the proton exchange membrane, and an anode diffusion layer overlying the anode catalyst layer. The cathode diffusion layer has a water vapor permeance of less than about 3×10−4 g/(Pa s m2) at 80° C. and 1 atmosphere. The invention also relates to cathode diffusion layers for fuel cell systems.
摘要:
A diffusion media is provided for implementation with a PEM fuel cell. The diffusion media is a permeable sheet that is rigid along a transverse axis, flexible along a lateral axis and has a substantially incompressible thickness. The diffusion media is able to be mass produced in large sheets and rolled along the lateral axis for transport and storage. The rigidity of the transverse axis is provided by either inclusion of larger fibers or metallic strips aligned in the transverse direction and prevents tenting of the diffusion media into flow channels of the PEM fuel cell. The diffusion media is water and gas permeable and electrically conductive.