摘要:
A method for vaporization of liquid hydrocarbon fuel wherein liquid hydrocarbon fuel is mixed with vapor to provide a vapor product which is heated. The heated vapor product is mixed with additional liquid hydrocarbon fuel to provide a second vapor product comprising vaporized hydrocarbon fuel. The heating of vapor product and mixing of additional liquid hydrocarbon fuel can be done until a desired amount of liquid hydrocarbon fuel is vaporized.
摘要:
A procedure for shutting down an operating fuel cell system that recirculates a portion of the anode exhaust in a recycle loop, includes disconnecting the primary load from the external circuit, stopping the flow of air to the cathode, and applying an auxiliary resistive load across the cells to reduce and/or limit cell voltage and reduce the cathode potential while fuel is still flowing to the anode and the anode exhaust is recirculating. The fuel flow is then stopped, but the anode exhaust continues to be circulated in the recycle loop to bring the hydrogen therein into contact with a catalyst in the presence of oxygen to convert the hydrogen to water, such as in a catalytic burner. The recirculating is continued until substantially all the hydrogen is removed. The cell may then be completely shut down. No inert gas purge is required as part of the shut-down process.
摘要:
The present invention discloses a corrosion resistant fuel cell in which an ion impermeable protective layer is positioned over at least a portion of the noncatalyzed carbon based components. This layer prevents reactant ions or molecules form reaching localized high potential areas of these components and corroding the carbon material.
摘要:
Fuel Cell stack coolant water is processed by moving the two-phase water/steam coolant exhaust through a steam separator wherein the water phase is separated from the steam phase. The water phase is then moved through a heat exchanger where its temperature is lowered to a subcooled level which is below the coolant operating temperature in the stack. A flow control valve is associated with the coolant heat exchanger to regulate water flow through and/or around the heat exchanger depending on the temperature of the water which leaves the steam separator. By subcooling the coolant before it reenters the stack, a lessening of electrolyte loss through evaporation is achieved. By eliminating steam condensation as a form of system heat rejection, system engineering is simplified and construction costs are lowered.
摘要:
A fuel cell (10), having a proton exchange membrane (48), an anode and a cathode, and cathode and anode water transport plates (12, 16), includes a water capillary edge seal to optimize and greatly improve fuel cell operation without the need for additional seals or impregnation of the water transport plates. The water filled porous bodies of the water transport plates (12, 16) use the capillary forces of the water, which is a product of the electrochemical reaction of the fuel cell (10) and the preferred coolant, to prevent gas intrusion into the water system and over board leakage of the gases as well as the resultant hazardous mixture of gaseous fuel and oxidizing gas.
摘要:
A simplified solid polymer electrolyte fuel cell power plant utilizes porous conductive separator plates having central passages which are filled with circulating coolant water. The coolant water passes through a heat exchanger which rejects heat generated in the power plant. Water appearing on the cathode side of each cell membrane is pumped into the water circulation passages through the porous oxidant reactant flow field plates by a positive .DELTA.P created between the cathode reactant flow field of each cell and the coolant water circulation passages between each cell. In order to create the desired .DELTA.P, at least one of the reactant gas streams will be referenced to the coolant water loop so as to create a coolant loop pressure which is less than the referenced reactant gas stream pressure. Excess water is removed from the coolant water stream. The system can operate at ambient or at elevated pressures. Each cell in the power plant is individually cooled on demand, and the power plant does not require a separate cooling section or reactant stream humidifying devices.
摘要:
A heat exchanger uses the heat from processed fuel gas from a reformer for a fuel cell to superheat steam, to preheat raw fuel prior to entering the reformer and to heat a water-steam coolant mixture from the fuel cells. The processed fuel gas temperature is thus lowered to a level useful in the fuel cell reaction. The four temperature adjustments are accomplished in a single heat exchanger with only three heat transfer cores. The heat exchanger is preheated by circulating coolant and purge steam from the power section during startup of the latter.
摘要:
A fuel cell system that includes fuel processing components, such as a reformer and shift converter, for converting an organic fuel to hydrogen, is shut-down by disconnecting the fuel cell from its load and purging the fuel processing components of residual hydrogen with a flow of air. The purge air may be forced through the components in series or in parallel, using a blower; or, the purge air may be allowed to enter the components through a low inlet, whereupon the air rises through the components by natural circulation and exits through a high outlet, along with the residual hydrogen.
摘要:
A proton exchange membrane (PEM) fuel cell includes fuel and oxidant flow field plates (26, 40) having fuel and oxidant channels (27, 28; 41, 44), and water channels, the ends (29, 48) of which that are adjacent to the corresponding reactant gas inlet manifold (34, 42) are dead ended, the other ends (31, 50) draining excess water into the corresponding reactant gas exhaust manifold (36, 45). Flow restrictors (39, 47) maintain reactant gas pressure above exit manifold pressure, and may comprise interdigitated channels (65, 66; 76, 78). Solid reactant gas flow field plates have small holes (85, 88) between reactant gas channels (27, 28; 41) and water drain channels (29, 30; 49, 50). In one embodiment, the fuel cells of a stack may be separated by either coolant plates (51) or solid plates (55) or both. In a second embodiment, coolant plates (51a) have weep holes (57) that inject water into the ends (29) of the reactant gas water channels which are in the region of the inlet manifold (34), thereby assuring humidification of the reactants.
摘要:
A method and system are provided for controlling a fuel cell power plant (10). A demand signal (Mld) representing the anticipated current/power required by the electrical load(s) is provided. A current signal (Iap) representative of the actual current drawn by the load(s) (20) is provided. The greater of the demand signal (Mld) and the current signal (Iap) is selected (46) and utilized to provide a control signal (Mx, Mx′, Mx″) for regulating one or more of the reactants and coolant (24). One or more status signals (Xp, Xp′, Xp″, Vap) indicative of the status of a regulated one of more of the reactant/coolant and/or a respective operating process effected, is provided. Each status signal is transformed to a respective load capability signal (61, 61′, 61″). The lesser of the demand signal (Mld) and each of the load capability signals (61, 61′, 61 ″) is selected (62) to provide an output signal (Mi) for commensurately controlling a system load (20, 32).