摘要:
The invention is a hydrogen passivation shut down system for a fuel cell power plant (10). An anode flow path (24) is in fluid communication with an anode catalyst (14) for directing hydrogen fuel to flow adjacent to the anode catalyst (14), and a cathode flow path (38) is in fluid communication with a cathode catalyst (16) for directing an oxidant to flow adjacent to the cathode catalyst (16) of a fuel cell (12). Hydrogen fuel is permitted to transfer between the anode flow path (24) and the cathode flow path (38). A hydrogen reservoir (66) is secured in fluid communication with the anode flow path (24) for receiving and storing hydrogen during fuel cell (12) operation, and for releasing the hydrogen into fuel cell (12) whenever the fuel cell (12) is shut down.
摘要:
The invention is a start up system and method for a fuel cell power plant (10) using a purging of the cathode flow field (38) with a hydrogen rich reducing fluid fuel to minimize corrosion of the cathode electrode (16). The method for starting up the shut down fuel cell power plant (10) includes the steps of: a. purging the cathode flow field (38) with the reducing fluid fuel; b. then, directing the reducing fluid fuel to flow through an anode flow field (28); c. next, terminating flow of the fuel through the cathode flow field (38) and directing an oxygen containing oxidant to flow through the cathode flow field (38); and, d. finally, connecting a primary load (70) to the fuel cell (12) so that electrical current flows from the fuel cell (12) to the primary load (70).
摘要:
The invention is a system and method for shutting down a fuel cell power plant having at least one fuel cell, a primary load, and an auxiliary load that receive electrical current from electrodes of the fuel cell through an external circuit. Shutting down the plant includes disconnecting the primary load; terminating flow of the oxidant through a cathode flow field; connecting the auxiliary load to consume oxygen within the fuel cell; disconnecting the auxiliary load; connecting a power supply to the fuel cell electrodes to increase a concentration of hydrogen within the cathode flow field; and, then, decreasing or eliminating flow of hydrogen into an anode flow field after an equilibrium gas concentration of at least 0.0001% hydrogen, balance fuel cell inert gases, is achieved in both the anode and cathode flow fields.
摘要:
A PEM fuel cell system includes a plurality of PEM fuel cells arranged in a stack having two opposed, outwardly facing end surfaces; pressure plates positioned relative to said end surfaces for securing said PEM fuel cells in said stack; and spacer members between said end surfaces and said pressure plates for thermally insulating said end surfaces from said pressure plates.
摘要:
A molten carbonate fuel cell matrix material is described made up of a matrix tape portion and a bubble barrier portion. The matrix tape portion comprises particles inert to molten carbonate electrolyte, ceramic particles and a polymeric binder, the matrix tape being flexible, pliable and having rubber-like compliance at room temperature. The bubble barrier is a solid material having fine porosity up to about 50% by volume, optionally being bonded to the matrix tape. In operation in a fuel cell, the polymer binder burns off leaving the matrix and bubble barrier providing superior sealing, stability and performance properties to the fuel cell stack.
摘要:
A method of operating a fuel cell power plant (10) including a stack (11) of fuel cells having an anode catalyst layer and a cathode electrode (15) including a catalyst layer disposed on catalyst support material is characterized by, during normal operation of said power plant, adjusting the voltage of the stack to be substantially equal to or less than a predetermined maximum voltage for the temperature of the stack. Further, said step of adjusting comprises adjusting the stack voltage to the lesser of: a) a predetermined voltage above which corrosion of catalyst support material is significant and below which corrosion of catalyst support material is insignificant at the temperature of the stack; and b) a predetermined voltage above which dissolution of catalyst is significant and below which dissolution of the catalyst is insignificant at the temperature of the stack.
摘要:
A fuel cell stack (32) includes a plurality of fuel cells in which each fuel cell is formed between a pair of conductive, porous, substantially hydrophilic plates (17) having oxidant reactant gas flow field channels (12-15) on a first surface and fuel reactant gas flow field channels (19, 19a) on a second surface opposite to the first surface, each ˜f the plates being separated from a plate adjacent thereto by a unitized electrode assembly (20) including a cathode electrode (22), having a gas diffusion layer (GDL) an anode electrode (23) having a GDL with catalyst between each GDL and a membrane (21) disposed therebetween. Above the stack is a condenser (33} having tubes (34) that receive coolant air (39, 40} to condense water vapor out of oxidant exhaust in a chamber (43). Inter-cell wicking strips (26) receive condensate and conduct it along the length of the stack to all cells. In-cell wicking strips (1G, 1 ˜a) on one or both surfaces conduct the water from the inter-cell wicking strips downwardly along the entire planform of each cell. Reactant air is provided to an air inlet manifold (47) through an air inlet conduit (48) from an air pump (49).
摘要:
Water in a fuel cell accumulator is kept above freezing by a hydrogen/oxygen catalytic combustor fed hydrogen through a mechanical thermostatic valve in thermal communication with the container and connected to a hydrogen supply. The system includes an ejector hydrogen/oxygen combustor and a diffusion hydrogen/oxygen combustor for warming a medium within a container such as water in the accumulator of a fuel cell in response to a mechanic hydrostatic valve which conducts hydrogen to a combustor responsive to the temperature of the container.
摘要:
Water (9) in a fuel cell accumulator (10) is kept above freezing by a hydrogen/oxygen catalytic combustor (13) fed hydrogen through a mechanical thermostatic valve (25) in thermal communication (26) with the container (10) or the air nearby, and connected to hydrogen (28), optionally in series with a timer valve (183). The combustor may comprise an ejector (32) having hydrogen through its primary inlet (31) drawing air through a secondary inlet (33), or a diffusion combustor having a catalyst (38), including TEFLON® to permit water generated by combustion to flow by gravity out of the catalyst, spaced from a heating surface (30), and a diffusion control device (40); low partial pressure of oxygen at the catalyst causing diffusion through the device. Combustion vapor condenses on a surface (146) and is led by hydrophilic woven carbon paper (126) and wicking material (133) downwardly, through a disk (140) and plugs (147) either to ambient to a salt canister (190), or to a porous hydrophilic mixer (200) for mixture with antifreeze (206).
摘要:
A fuel cell stack (32) includes a plurality of fuel cells in which each fuel cell is formed between a pair of conductive, porous, substantially hydrophilic plates (17) having oxidant reactant gas flow field channels (12-15) on a first surface and fuel reactant gas flow field channels (19, 19a) on a second surface opposite to the first surface, each ˜f the plates being separated from a plate adjacent thereto by a unitized electrode assembly (20) including a cathode electrode (22), having a gas diffusion layer (GDL) an anode electrode (23) having a GDL with catalyst between each GDL and a membrane (21) disposed therebetween. Above the stack is a condenser (33} having tubes (34) that receive coolant air (39, 40) to condense water vapor out of oxidant exhaust in a chamber (43). Inter-cell wicking strips (26) receive condensate and conduct it along the length of the stack to all cells. In-cell wicking strips (1G. 1˜a) on one or both surfaces conduct the water from the inter-cell wicking strips downwardly along the entire planform of each cell. Reactant air is provided to an air inlet manifold (47) through an air inlet conduit (48) from an air pump (49).