Abstract: During periods of vehicle inactivity, a vehicle-based APU electric generating system may be coupled into a regional electric grid to send electricity into the grid. A currently-preferred APU is a solid oxide fuel cell system. When a large number of vehicles are thus equipped and connected, substantial electric buffering can be effected to the grid load. A vehicle-based APU can also function as a back-up generator to a docking facility in the event of power failure of the grid. Gaseous hydrocarbon is readily supplied by pipe in many locations as a commercial and residential heating fuel source, and a hydrocarbon reformer on the vehicle can be attached to the fuel source, enabling an APU to operate as a stationary power source indefinitely. An optional storage tank on the vehicle may be refueled with gaseous fuel, for example, while the battery is being electrically recharged by the grid.

Abstract: An SOFC fuel cell stack system in accordance with the invention including a recycle flow leg for recycling a portion of the anode tail gas into the inlet of an associated hydrocarbon reformer supplying reformate to the stack. The recycle leg includes a controllable pump for varying the flow rate of tail gas. Preferably, a heat exchanger is provided in the leg ahead of the pump for cooling the tail gas via heat exchange with incoming cathode air. A low-wattage electrical reheater is also preferably included between the heat exchanger and the pump to maintain the temperature of tail gas entering the pump, during conditions of low tail gas flow, at a drybulb temperature above the dewpoint of the tail gas.

Abstract: Apparatus and method for operating a fuel cell system including a hydrocarbon catalytic reformer and close-coupled fuel cell stack by recycling anode syngas into the reformer in a range between 60% and 95% of the total syngas. At equilibrium conditions, oxygen required for reforming of hydrocarbon fuel is derived from endothermically reformed water and carbon dioxide in the syngas. Reforming temperature is between about 650° C. to 750° C. The stack exit temperature is about 800° C. to 880° C. such that the required endotherm can be provided by the sensible heat of the recycled syngas. The stack has approximately equal anode and cathode gas flows in opposite directions, resulting in cooling from both the anodes and cathodes.

Abstract: A solid-oxide fuel cell stack assembly comprising a plurality of sub-stacks, preferably two sub-stacks each containing one-half the total number of fuel cells. Cathode air and fuel gas are passed through the first sub-stack, wherein they are partially reacted and also heated. The exhaust cathode air and the exhaust fuel gas from the first sub-stack are directed to the respective inlets of the second sub-stack, becoming the supply cathode air and fuel gas therefor. A first heat exchanger in the flow paths between the sub-stacks and a second heat exchanger ahead of the sub-stacks can help to balance the performance of the two stacks. The result of dividing the number of cells into a plurality of sub-stacks, wherein the exhaust of one sub-stack becomes the supply for the next sub-stack, is that fuel efficiency and utilization are improved, thermal stresses are reduced, and electrical power generation is increased.

Abstract: An auxiliary power system providing electric power from a fuel cell stack at a nominal steady state output experiences an instantaneous voltage drop when maximum load is called for, which voltage drop can damage the fuel cell stack. Also, the required power increase cannot be provided for a short lag period during which the fuel cell fueling is ramped up. In the present invention, an electricity storage device, such as a battery, is provided in parallel with the fuel cell stack to meet the burst power demand during the fuel cell ramp-up lag. Various alternative control mechanisms are disclosed to assure that the necessary power is provided while also protecting both the fuel cell stack and the battery from damaging voltage swings. A vehicular application with a shared vehicle battery is also disclosed.

Abstract: A system for co-generation of electricity combining a hydrocarbon catalytic reformer, an SOFC assembly and a generator driven by a gas turbine. The fuel cell assembly recycles a high percentage of anode exhaust gas into the reformer. Oxygen for reforming is derived from water in an endothermic process. The stack exit temperature is normally above 800° C. DC power from the fuel cell assembly and AC power from the gas turbine generator are directed to a power conditioner. Anode exhaust gas including carbon monoxide and hydrogen is divided into a plurality of portions by which heat may be added to the reforming, gas turbine, and cathode air heating processes. Water may be recovered from the exhaust. A power system in accordance with the invention is capable of operating at a higher total efficiency than either the fuel cell component or the gas turbine component alone.

Abstract: A fuel cell system comprising a plurality of fuel cell stacks. The stacks may be connected electrically in any sequence desired, such as in series, in parallel, or in combinations thereof or electrically independent. The electrical performance of each stack is optimized by some metric or the operating temperature of the stack is controlled by controlling the internal operating temperature of the stack, which in turn is controlled by controlling the output voltage, output current, or load of each stack independently of the other stacks. In large fuel cell systems having a large plurality of stacks, adjacent stacks may of necessity be grouped as stack pairs with joint electrical control rather than individual control, but at some sacrifice in optimal operation.

Abstract: An improved method and apparatus for providing reformate into an engine exhaust stream including aftertreatment devices such as a particulate trap and an NOx filter regenerable by hydrogen-rich reformate injected into the engine exhaust ahead of the aftertreatment devices. A pump pressurizes a hydrocarbon catalytic reformer, and a three-way valve for dividing the reformate injected into the engine exhaust. The reformer draws oxygen from the engine exhaust rather than ambient air as in the prior art. Thus, the only pressure drop that the pump/reformer system must overcome is within the reformate supply system between the reformer take-off point and the reformate entry points. In a configuration wherein the exhaust is taken off ahead of the inline particulate trap, a separate particulate filter is preferably incorporated into the reformer supply line.

Abstract: liquid fuel reformer apparatus includes a reactor tube having at a first end and injector for introducing droplets of liquid fuel and an inlet for introducing an air flow, and at a second end an outlet for discharging a reformate fuel stream. A reforming catalyst for converting the liquid fuel to the reformate fuel stream is disposed within the reactor tube, and at least one regulator member is disposed between the first end of the tube and the catalyst. At least a portion of the regulator member is permeable to the liquid fuel and to air flow.

Abstract: An improved method and apparatus for providing reformate into an engine exhaust stream including aftertreatment devices such as a particulate trap and an NOx filter regenerable by hydrogen-rich reformate injected into the engine exhaust ahead of the aftertreatment devices. A pump pressurizes a hydrocarbon catalytic reformer, and a three-way valve for dividing the reformate injected into the engine exhaust. The reformer draws oxygen from the engine exhaust rather than ambient air as in the prior art. Thus, the only pressure drop that the pump/reformer system must overcome is within the reformate supply system between the reformer take-off point and the reformate entry points. In a configuration wherein the exhaust is taken off ahead of the inline particulate trap, a separate particulate filter is preferably incorporated into the reformer supply line.

Abstract: An SOFC fuel cell stack system in accordance with the invention including a recycle flow leg for recycling a portion of the anode tail gas into the inlet of an associated hydrocarbon reformer supplying reformate to the stack. The recycle leg includes a controllable pump for varying the flow rate of tail gas. Preferably, a heat exchanger is provided in the leg ahead of the pump for cooling the tail gas via heat exchange with incoming cathode air. A low-wattage electrical reheater is also preferably included between the heat exchanger and the pump to maintain the temperature of tail gas entering the pump, during conditions of low tail gas flow, at a drybulb temperature above the dewpoint of the tail gas.

Abstract: In one embodiment, a reformer system can comprise an exhaust treatment device, a reformer disposed upstream of and in fluid communication with the exhaust treatment device, an oxygen storage device disposed upstream of and in fluid communication with the reformer, and a first fluid moving device disposed upstream of and in fluid communication with the oxygen storage device. In anther embodiment, a reformer system can comprise an exhaust treatment device, a reformer disposed upstream of and in fluid communication with the exhaust treatment device, a reformate storage device disposed downstream of and in fluid communication with the reformer, and a fluid moving device disposed upstream of and in fluid communication with the reformate storage device.

Abstract: During periods of vehicle inactivity, a vehicle-based APU electric generating system may be coupled into a regional electric grid to send electricity into the grid. A currently-preferred APU is a solid oxide fuel cell system. When a large number of vehicles are thus equipped and connected, substantial electric buffering can be effected to the grid load. A vehicle-based APU can also function as a back-up generator to a docking facility in the event of power failure of the grid. Gaseous hydrocarbon is readily supplied by pipe in many locations as a commercial and residential heating fuel source, and a hydrocarbon reformer on the vehicle can be attached to the fuel source, enabling an APU to operate as a stationary power source indefinitely. An optional storage tank on the vehicle may be refueled with gaseous fuel, for example, while the battery is being electrically recharged by the grid.

Abstract: A solid-oxide fuel cell stack assembly comprising a plurality of sub-stacks, preferably two sub-stacks each containing one-half the total number of fuel cells. Cathode air and fuel gas are passed through the first sub-stack, wherein they are partially reacted and also heated. The exhaust cathode air and the exhaust fuel gas from the first sub-stack are directed to the respective inlets of the second sub-stack, becoming the supply cathode air and fuel gas therefor. A first heat exchanger in the flow paths between the sub-stacks and a second heat exchanger ahead of the sub-stacks can help to balance the performance of the two stacks. The result of dividing the number of cells into a plurality of sub-stacks, wherein the exhaust of one sub-stack becomes the supply for the next sub-stack, is that fuel efficiency and utilization are improved, thermal stresses are reduced, and electrical power generation is increased.

Abstract: Apparatus and method for operating a fuel cell system including a hydrocarbon catalytic reformer and close-coupled fuel cell stack by recycling anode syngas into the reformer in a range between 60% and 95% of the total syngas. At equilibrium conditions, oxygen required for reforming of hydrocarbon fuel is derived from endothermically reformed water and carbon dioxide in the syngas. Reforming temperature is between about 650° C. to 750° C. The stack exit temperature is about 800° C. to 880° C. such that the required endotherm can be provided by the sensible heat of the recycled syngas. The stack has approximately equal anode and cathode gas flows in opposite directions, resulting in cooling from both the anodes and cathodes.

Abstract: A system for co-generation of electricity combining a hydrocarbon catalytic reformer, an SOFC assembly and a generator driven by a gas turbine. The fuel cell assembly recycles a high percentage of anode exhaust gas into the reformer. Oxygen for reforming is derived from water in an endothermic process. The stack exit temperature is normally above 800° C. DC power from the fuel cell assembly and AC power from the gas turbine generator are directed to a power conditioner. Anode exhaust gas including carbon monoxide and hydrogen is divided into a plurality of portions by which heat may be added to the reforming, gas turbine, and cathode air heating processes. Water may be recovered from the exhaust. A power system in accordance with the invention is capable of operating at a higher total efficiency than either the fuel cell component or the gas turbine component alone.

Abstract: Method and control system for controlling propulsion equipment in a hybrid vehicle including a traction motor and a propulsion unit, such as an internal combustion engine or a fuel cell, are provided. In one implementation, the control system includes a sensor coupled to sense a signal indicative of vehicle torque demand. The control system further includes memory for storing a threshold torque range indicative of conditions of relatively low vehicle torque demand. A processor is configured to process the signal indicative of vehicle torque demand to determine whether the vehicle torque demand is within the threshold torque range. During conditions when the signal indicative of vehicle torque demand is within the threshold torque range, an actuator is configured to generate a signal configured to activate the electric traction motor to drivingly propel the vehicle while de-engaging the internal combustion engine from propelling the vehicle.

Abstract: Method and control system for controlling propulsion equipment in a hybrid vehicle including a traction motor and a propulsion unit, such as an internal combustion engine or a fuel cell, are provided. In one implementation, the control system includes a sensor coupled to sense a signal indicative of vehicle torque demand. The control system further includes memory for storing a threshold torque range indicative of conditions of relatively low vehicle torque demand. A processor is configured to process the signal indicative of vehicle torque demand to determine whether the vehicle torque demand is within the threshold torque range. During conditions when the signal indicative of vehicle torque demand is within the threshold torque range, an actuator is configured to generate a signal configured to activate the electric traction motor to drivingly propel the vehicle while de-engaging the internal combustion engine from propelling the vehicle.