摘要:
A fuel cell system, which may be powering a vehicle propulsion system (159), includes a fuel cell power plant having a stack (151) including a plurality of fuel cells (12), each having a cathode (19) and anode (17) separated by a membrane (16), and an air pump (174) connected to reactant air flow fields through a diverter valve (172). A controller (185) is responsive to normal and high demand to cause the diverter valve to allow air to flow from the pump to the reactant air flow fields, and is responsive to low demand to cause said diverter valve to divert air directly into ambient so that it does not reach the cathode, thereby to reduce open circuit voltage conditions that promote degradation of the cathode, and to prevent excessive performance decay. An auxiliary load (220) can be in the diverted air flow, either ahead of or after the diverter valve. Energy storage (200, 201) works with the vehicle propulsion system.
摘要:
The invention is a porous carbon body for a fuel cell having an electronically conductive hydrophilic agent and method of manufacture of the body. The porous carbon body comprises an electronically conductive graphite powder in an amount of between 60%-80% by weight of the body; a carbon fiber in an amount of between 5%-15% by weight of the body; a thermoset binder in an amount of between 6%-18% by weight of the body; and, a modified carbon black electronically conductive hydrophilic agent in an amount of between 2%-20% by weight of the body. The body provides for increased wettability without any decrease in electrical conductivity, and also provides for an efficient manufacture without any need for high temperature, costly steps to graphitize the body, or to incorporate post molding hydrophilic agents into pores of the body.
摘要:
Disclosed is a fuel cell stack assembly for use in a fuel cell power plant and for producing electricity from fuel and oxidizer reactants. The fuel cell stack assembly includes a plurality of individual fuel cells each having an electrolytic medium, a cathode and an anode, and the cell stack assembly is adapted for defining anode flow fields for exposing the anodes to a fuel, cathode flow fields for exposing the cathodes to an oxidant. Also included are input and output manifolds defining input and output inner volumes in fluid communication with the cathode flow fields, and at least one blower mounted with one of the manifolds for flowing oxidizer through cathode flow fields. The blower can be mounted within an inner volume defined by a manifold, and can be a vane axial or centrifugal blower, and can be driven by a variable speed motor. Multiple blowers can be associated with the cell stack assembly, and can either push or pull (or both) the oxidizer through the cathode flow fields. In a fuel cell stack assembly having fuel cells arranged in separate stacks, each stack has a blower associated therewith.
摘要:
A matrix material for a molten carbonate fuel cell is described which is flexible, pliable and has rubber-like compliance at room temperature. The matrix has three components comprising fine inert particulate material, larger crack attenuating ceramic particulate material, and an organic polymeric binder. A process of assembling a molten carbonate fuel cell utilizing the compliant matrix material is also described. The compliant matrix material is inserted into a molten carbonate fuel cell stack utilizing fuel cell anodes with sufficient porosity to contain excess electrolyte. The fuel cell is heated up to a temperature sufficient to remove the polymer binder and cause a portion of the electrolyte material present in the anode to wick into the matrix to substantially fill it completely.
摘要:
A matrix material for a molten carbonate fuel cell is described which is flexible, pliable and has rubber-like compliance at room temperature. The matrix has three components comprising fine inert particulate material, larger crack attenuating ceramic particulate material, and an organic polymeric binder. A process of assembling a molten carbonate fuel cell utilizing the compliant matrix material is also described. The compliant matrix material is inserted into a molten carbonate fuel cell stack utilizing fuel cell anodes with sufficient porosity to contain excess electrolyte. The fuel cell is heated up to a temperature sufficient to remove the polymer binder and cause a portion of the electrolyte material present in the anode to wick into the matrix to substantially fill it completely.
摘要:
A cooler for removing waste heat from a stack of fuel cells includes a plurality of tubes for carrying the coolant through the stack. The tubes are disposed adjacent the nonelectrolyte side of electrodes in the stack in grooves or passageways formed in the surface of plates which separate one cell in the stack from another. Since the tubes are exposed to the electrolyte used in the stack they must be made from or at least include a protective coating of material which is stable in the electrolyte. Preferably this material is also a dielectric to prevent shunt currents from passing into the tubes and coolant which may be water.
摘要:
Fuel cell stacks (20) include fuel cells (22) in which internal pressure on membranes (28), caused by adjacent cross points (19) or ribs (9, 17) of gas flow field plates (7, 33) is reduced by lowering the axial load holding the stack together, after an initial high axial load, that establishes minimal possible internal resistance, has been held for between a few hours and 20 hours. The need for robust axial load restraints is also reduced. Pressure of cross points (19) can also be spread by stiffening components or adding stiffeners.
摘要:
In a fuel cell stack, an inlet fuel distributor (15, 31, 31a, 31b) comprises a plurality of fuel distributing passageways (17-23, 40-47, 64) of substantially equal length and equal flow cross section to uniformly distribute fuel cell inlet fuel from a fuel supply conduit (13, 14, 50) to a fuel inlet manifold (28). The conduits may be either channels (40-47; 64) formed within a plate (39) or tubes (17-23). The channels may have single exits (65) or double exits (52, 53) into the fuel inlet manifold.
摘要:
A process for shutting down a fuel cell power plant (5) shuts off (40) process air, recycles (44-46) air exhaust 42 to air inlets 34, and connects an auxiliary load to the stack (6). Coulombs are counted by integrating (17) current (73) or voltage (75) to the load to determine when all oxygen in the air side (10, 27, 30, 34, 42, 44-47) of the power plant is consumed and a desired concentration of hydrogen is transferred to the air side of the power plant. The speed of the shutdown processes may be increased by increasing fuel pressure (15) or adding a battery (78) in series with the auxiliary load.
摘要:
A polymer electrolyte membrane (PEM) fuel cell power plant is cooled evaporatively by a non-circulating pressurized water coolant system. The coolant system utilizes a hydrophobic porous plug for bleeding air from from the coolant water while maintaining coolant back pressure in a coolant flow field of the system. Furthermore, there is a first method for identifying appropriate parameters of the hydrophobic porous plug for use with a known particular coolant system; and a second method for determining proper operating conditions for a fuel cell water coolant system which can operate with a hydrophobic porous plug closure having known physical parameters.