Abstract:
During testing, a controllable condition of the fuel cell is controlled based on a control value, and a measurable condition of the fuel cell is measured to provide a data value. A data processor receives a user-readable input value and provides a user-readable output value. The user-readable input value is converted to the control value and the data value is converted to the user readable output value. A mapped file is generated by and is accessible by the data processor. The mapped file includes a plurality of tag records including a control tag record for storing the control value and a data tag record for storing the data value.
Abstract:
Apparatus and methods of ceasing operation of an electric power generating system improve the cold starting capability of the system. The system comprises a fuel cell stack connectable to an external circuit for supplying power to the external circuit. The stack comprises at least one solid polymer fuel cell, and the system further comprises a fuel passage for directing a fuel stream through the stack and an oxidant passage for directing an oxidant stream through the stack, a sensor assembly connected to the stack for monitoring a parameter indicative of stack performance, a controller for controlling at least one stack operating parameter, and a control system communicative with the sensor assembly and stack operating parameter controller. The method comprises adjusting at least one stack operating parameter to cause the stack to operate under a drying condition that causes a net outflux of water from the stack, operating the stack under the drying condition until the water content in the stack has been reduced, and interrupting supply of power from the stack to the external circuit.
Abstract:
A measuring method first calculates the conductivity of an electrolyte membrane based on measured output voltage and output current of a fuel cell. The water content of an oxidant channel as an index of present water content (PWC) of the fuel cell is calculated based on the calculated conductivity and the other measured physical quantities of the fuel cell. Further the method calculates the water content of the oxidant channel after the inside of the fuel cell reaches a steady state as an index of future water content (FWC) using the measured physical quantities. The PWC index and FWC index are compared, and it is finally determined, based on the result of the comparison and the difference between the previous and present values of the conductivity, whether the water content of the fuel cell is short or excessive at the present time.
Abstract:
Fuel cell power systems, direct current voltage converters, fuel cell power generation methods, power conditioning methods and direct current power conditioning methods are provided. According to one aspect of the invention, a fuel cell power system includes a plurality of terminals adapted to couple with a load; a fuel cell configured to convert chemical energy into direct current electrical energy having a variable voltage potential; and a converter coupled intermediate the fuel cell and the terminals, the converter being configured to convert the direct current electrical energy having the variable voltage potential into direct current electrical energy having a substantially constant voltage potential.
Abstract:
A method of operating a fuel cell power system includes providing a fresh hydrogen fuel to power modules that each contain a heater and a stack of fuel cells, providing a fuel exhaust containing hydrogen and water from the stack to a condenser, removing water from the fuel exhaust to generate a recycled fuel containing dewatered hydrogen, and pressurizing and recycling the recycled fuel output from the condenser to the power modules. The removed water may be vaporized in a stack cathode exhaust.
Abstract:
A method of shutting down operation of a fuel cell system is disclosed, comprising a fuel cell stack, the method comprising the sequential steps of: i) ceasing a supply of fuel to the fuel cell stack; ii) closing a shut-off valve on an exhaust line in fluid communication with a cathode system of the fuel cell system, the cathode system comprising a cathode fluid flow path passing through the fuel cell stack; iii) pressurizing the cathode system with an air compressor in fluid communication with a cathode air inlet port in the fuel cell stack; and iv) ejecting water from the cathode flow path.
Abstract:
A fuel cell assembly comprising an enclosure having a fuel cell stack mounted therein. The fuel cell stack has an inlet face for receiving coolant/oxidant fluid and an outlet face for expelling said coolant/oxidant fluid. The fuel cell stack further includes a pair of end faces extending transversely between the inlet face and outlet face. The enclosure defines a flow path for the coolant/oxidant fluid that is configured to guide the coolant/oxidant fluid to the inlet face, from the outlet face, and over at least one of the end faces.
Abstract:
A method for operating a solid oxide fuel cell having cathode-anode-electrolyte units, each including a first electrode for an oxidizing agent, a second electrode for combustible gas, and a solid electrolyte there between forming a metal interconnection between the CAE-units. The interconnect including a combustible gas distribution structure, and a second metallic gas distribution element having two channels for the oxidizing agent and separate channels for a tempering fluid. Cooling the second gas distribution element and a base layer of the first gas distribution element with the tempering fluid (O2). Measuring the first and second control temperatures T1 and T2. T1 being the tempering fluid temperature entering the fluid inlet side of the fuel cell. T2 being the tempering fluid temperature leaving the second gas distribution element. Where the amount of tempering fluid supplied to the second gas distribution element is controlled based on the difference between T1 and T2.
Abstract:
A solid oxide fuel cell or a solid oxide electrolyzing cell includes a) a plurality of cathode-anode-electrolyte units, each CAE-unit having a first electrode for an oxidizing agent, a second electrode for a combustible gas, and a solid electrolyte between the first electrode and the second electrode and b) a metal interconnect between the CAE-units. The interconnect having a first gas distribution element and a gas distribution structure for the combustible gas, wherein the first gas distribution element is in contact with the second electrode of the CAE-unit, and a second gas distribution element having channels for the oxidizing agent and including separate channels for a tempering fluid. The channels for the oxidizing agent are in contact with the first electrode of an adjacent CAE-unit, and the first gas distribution element and the second gas distribution element being electrically connected.
Abstract:
A fuel cell assembly comprising an enclosure having a fuel cell stack mounted therein, and an inlet opening into the enclosure. The fuel cell stack having an inlet face for receiving coolant/oxidant fluid. The fuel cell assembly further comprises a delivery gallery extending from the inlet in the enclosure to the inlet face of the fuel cell stack, the delivery gallery having a first region and a second region separated by an aperture. The delivery gallery and aperture are configured such that, in use, coolant/oxidant fluid within the first region of the delivery gallery is turbulent, and coolant/oxidant fluid within the second region of the delivery gallery has a generally uniform pressure.