摘要:
A method for purging water from a fuel cell stack at fuel cell system shutdown. The method includes determining a stack water generation request to control the rate of drying of membranes in the stack and determining a cathode catalytic heating water generation request. A maximum charge a battery in the fuel cell system can accept is also determined. An ancillary power request for powering components of the fuel cell system during shutdown is determined. The method allocates how much of the water generation request will be fulfilled by operating the fuel cell stack to charge the battery and to provide the power needed for the ancillary power request, and how much of the water generation request will be fulfilled by cathode catalytic heating that produces water and heat in a cathode side of the fuel cell stack.
摘要:
A method for purging water from a fuel cell stack at fuel cell system shutdown. The method includes determining a stack water generation request to control the rate of drying of membranes in the stack and determining a cathode catalytic heating water generation request. A maximum charge a battery in the fuel cell system can accept is also determined. An ancillary power request for powering components of the fuel cell system during shutdown is determined. The method allocates how much of the water generation request will be fulfilled by operating the fuel cell stack to charge the battery and to provide the power needed for the ancillary power request, and how much of the water generation request will be fulfilled by cathode catalytic heating that produces water and heat in a cathode side of the fuel cell stack.
摘要:
A fuel cell stack that includes catalyzed surfaces in the non-active inlet region of the cathode flow channels. At cold system start-up, hydrogen is introduced into the cathode inlet header to be mixed with air so that a chemical reaction is provided by the catalyst that generates heat to warm the cooling fluid in the non-active inlet area. Therefore, the cooling fluid that enters the active area of the stack will not be cold enough to quench the chemical reaction.
摘要:
A fuel cell system wherein a plurality of fuel cells are arranged in a series of stages, the number of fuel cells decreasing in number in each stage from anode gas inlet to the anode gas outlet. The system allows for parallel flow to all of the cells in a given stage and series flow between the various stages. A similar configuration is present on a cathode side of the system. However, the direction of flow is reversed, providing a greater number of cells in the stage nearest the cathode outlet and a fewer number of cells in the stage near the cathode gas inlet. The invention further provides for the various stages to be configured such that the direction of flow of the anode gas of a given stage is generally opposite the direction of flow of the cathode gas of a given stage.
摘要:
A fuel cell stack that includes catalyzed surfaces in the non-active inlet region of the cathode flow channels. At cold system start-up, hydrogen is introduced into the cathode inlet header to be mixed with air so that a chemical reaction is provided by the catalyst that generates heat to warm the cooling fluid in the non-active inlet area. Therefore, the cooling fluid that enters the active area of the stack will not be cold enough to quench the chemical reaction.
摘要:
A fuel processor for rapid start and operational control. The fuel processor includes a reformer, a shift reactor, and a preferential oxidation reactor for deriving hydrogen for use in creating electricity in a plurality of H2—O2 fuel cells. A heating and cooling mechanism is coupled to at least the shift reactor for controlling the critical temperature operation of the shift reactor without the need for a separate cooling loop. This heating and cooling mechanism produces or removes thermal energy as a product of the temperature of the combustion of air and fuel. Anode effluent and cathode effluent or air are used to control the temperature output of the heating mechanism. A vaporizer is provided that heats the PrOx reactor to operating temperature.
摘要:
A fuel cell including a water blocking layer positioned between anode gas flow channels and a gas diffusion media. The blocking layer prevents water from propagating through the gas diffusion media layer and entering the anode flow channels, while allowing gas from the flow channels to flow through the diffusion media layer to the membrane. A water accumulation channel can be provided around the perimeter of the gas diffusion media layer where blocked water is accumulated, and allowed to expand during cell freezing. A porous capillary wick can be provided in the accumulation channel for wicking water to the inlet end of the flow channels where it is used to humidify the anode gas coming into the fuel cell. The wick can have a tapered configuration so that it has a larger diameter at the gas input end of the flow channels.
摘要:
A fuel cell including a water blocking layer positioned between anode gas flow channels and a gas diffusion media. The blocking layer prevents water from propagating through the gas diffusion media layer and entering the anode flow channels, while allowing gas from the flow channels to flow through the diffusion media layer to the membrane. A water accumulation channel can be provided around the perimeter of the gas diffusion media layer where blocked water is accumulated, and allowed to expand during cell freezing. A porous capillary wick can be provided in the accumulation channel for wicking water to the inlet end of the flow channels where it is used to humidify the anode gas coming into the fuel cell. The wick can have a tapered configuration so that it has a larger diameter at the gas input end of the flow channels.
摘要:
A fuel cell system wherein a plurality of fuel cells are arranged in a series of stages, the number of fuel cells decreasing in number in each stage from anode gas inlet to the anode gas outlet. The system allows for parallel flow to all of the cells in a given stage and series flow between the various stages. A similar configuration is present on a cathode side of the system. However, the direction of flow is reversed, providing a greater number of cells in the stage nearest the cathode outlet and a fewer number of cells in the stage near the cathode gas inlet. The invention further provides for the various stages to be configured such that the direction of flow of the anode gas of a given stage is generally opposite the direction of flow of the cathode gas of a given stage.
摘要:
A bipolar plate for use in a fuel cell stack includes a first plate having a first coolant face with a first set of coolant channels formed therein. A second plate has a second coolant face with a second set of coolant channels formed therein. The first and second coolant faces are adjacent to one another to intermittently cross-link the first and second sets of coolant channels over a region of the first and second coolant faces.