摘要:
An example fuel cell assembly includes a separator plate. Non-porous and hydrophobic flow field layers are associated with the separator plate. An electrolyte retaining matrix comprises silicon carbide powder and has a mean particle size of about 3 microns and a thickness of about 0.05 mm Hydrophilic substrates are associated with catalyst layers. The hydrophilic substrates are about 70% porous and have a void volume that is about 40% filled with transferable phosphoric acid in an initial condition. A condensation zone cools a vapor passing from the assembly to less than about 140° C.
摘要:
An example fuel cell assembly includes a separator plate. Non-porous and hydrophobic flow field layers are associated with the separator plate. An electrolyte retaining matrix comprises silicon carbide powder and has a mean particle size of about 3 microns and a thickness of about 0.05 mm Hydrophilic substrates are associated with catalyst layers. The hydrophilic substrates are about 70% porous and have a void volume that is about 40% filled with transferable phosphoric acid in an initial condition. A condensation zone cools a vapor passing from the assembly to less than about 140° C.
摘要:
An ammonia contact scrubber system (10) for removing ammonia from a fuel stream for a fuel cell (16) includes a contact scrubber (12) having a scrubber fuel inlet (14) and a scrubber fuel exhaust (20) for directing flow of the fuel stream through support material (24) within the scrubber (12) and into the fuel cell (16). An acid circulating loop (26) has an acid holding tank (28) holding a liquid acid solution (30), an acid feed line (32) secured in fluid communication between the holding tank (28) and a scrubber acid inlet (36) of the contact scrubber (12), an acid return (38) for returning the acid solution from the scrubber (12) to the acid holding tank (28), and an acid circulation pump (42) for pumping the acid solution (30) through the acid circulating loop (26) and through the support material (24) within the scrubber (12).
摘要:
To evaporatively cool fuel cells, the pressure in steam carrying channels on one side of a hydrophobic porous liquid/vapor barrier layer disposed between adjacent fuel cells is reduced to below the vapor pressure of liquid water passing through liquid water carrying channels on the other side of the barrier layer, such as by using a vacuum pump. This causes some of the liquid water to boil and change to steam. The steam passes through the barrier layer into the steam channels and is carried out of the cells. The operating temperature of the fuel cell is adjusted by controlling the pressure within the steam channels, such as by controlling the amount of heat removed from the steam after it leaves the steam channels.
摘要:
In a fuel cell for a fuel cell power plant having a PEM (9), a cathode comprising at least a catalyst (10) and a support substrate (17), possibly with a diffusion layer (16), on one side of the PEM, and an anode comprising at least an anode support substrate (14) and an anode catalyst (11) on the opposite side of the PEM, and a porous water transport plate having reactant gas flow field channels (31, 32) (21, 28) adjacent to each of said support substrates as well as water flow channels (22) in at least one of said water transport plates, the thermal conductance of the cathode is less than about one-half of the thermal conductance of the anode, and preferably less than one-quarter of the thermal conductance of the anode, to promote flow of water from the cathode to the anode and to the adjacent water transport plate, obviating the need, in some cases, for water or reactant pressure pumps.
摘要:
A stack (11) of fuel cells have water flow channels receiving water through a pump (33) from an accumulator (29) having double walls (63, 66) with vacuum insulation panels (VIPs) (65, 68) therebetween, auxiliary DC power source (80) (battery or supercapacitor) is disposed in a container (43) having double walls (81, 86) with VIPs (65, 68) encapsulated therebetween. A keep-warm heater (51) keeps the source warm enough for at least half power capacity, the source driving its own heater as well as a keep-warm heater (50) in the accumulator to keep the accumulator above freezing. A microwave heater (58) disposed in the accumulator distributes energy to melt ice using fuel cell stack power upon startup.
摘要:
A fuel cell power plant has a fuel cell (38) receiving hydrogen (37) from a fuel processing system (12) which employs a vaporizer (19) to vaporize clean gasoline from a source (13). A conventional start burner (22) and startup heat exchanger (28) are utilized to convert water (31) from the fuel processing system (12) and fuel cell (38) into steam (32); but during sub-zero startup, an aqueous antifreeze solution (46) is provided to the heat exchanger (28) to produce the steam (32) for starting the vaporization of gasoline in the vaporizer (19).
摘要:
A seal structure 58 between adjacent porous plates 18, 20 and a method of making the seal structure for an electrochemical cell are disclosed. Various construction details are developed which facilitate fabrication and assembly. In one embodiment, the adjacent porous plates are electrolyte reservoir plates joined together at a three-layer seal structure to form an integral assembly.
摘要:
A porous plate for an electrochemical cell, such as plates 22, 24 having a sealing material disposed in an edge region 41 of the plate is disclosed. Various construction details including a method for making the plate are disclosed which increase the cross pressure material the plate can withstand. In one embodiment, the seal region 41 is impregnated with powder having a low structure and predetermined particle size using a pressurized liquid carrier.
摘要:
A cooling system 24 for an electrochemical cell stack 12 is disclosed. Various construction details which avoid plugging of the cooling system during long term operation with a cooling fluid having dissolved species and suspended particles, such as water, are discussed. The cooling system includes spaced apart cooler assemblies 30. Conduits 32 for supplying cooling fluid to the cooler assemblies include sets of cooling tubes 74 in serial flow communication.