Abstract: A fuel cell power plant (10) includes a fuel cell (12) having a membrane electrode assembly (MEA) (16), disposed between an anode support plate (14) and a cathode support plate (18), the anode and/or cathode support plates include a hydrophilic substrate layer (80, 82) having a predetermined pore size. The pressure of the reactant gas streams (22, 24) is greater than the pressure of the coolant stream (26), such that a greater percentage of the pores within the hydrophilic substrate layer contain reactant gas rather than water. Any water that forms on the cathode side of the MEA will migrate through the cathode support plate and away from the MEA. Controlling the pressure also ensures that the coolant water will continually migrate from the coolant stream toward the anode side of the MEA, thereby preventing the membrane from becoming dry. Proper pore size and a pressure differential between coolant and reactants improves the electrical efficiency of the fuel cell.

Abstract: Fuel exhaust (109) of a primary fuel cell stack (11) flows into an auxiliary fuel cell stack (12) which powers a DC storage (82) feeding a bi-directional DC/AC converter (86) that is switchable (89) to auxiliary equipment (90, 91) (such as pumps) to a main power bus (54) feeding a main load (55). Fresh fuel (97) is provided (98, 105) to the primary stack for 90% fuel utilization, with over 99% overall power plant fuel utilization. The auxiliary equipment (90, 91) may be powered by the bus (54).

Abstract: An internal combustion engine vehicle includes a compact light weight PEM fuel cell auxiliary power system (2) which is used to provide electrical power for operating the vehicle starter (10) to start the vehicle, and for operating additional electrical equipment while the vehicle is running, or before the vehicle is running. A small light weight dry cell battery (4) is included in the vehicle for supplying startup power for the PEM fuel cell auxiliary power system. The conventional heavy and bulky twelve volt battery is not needed in the vehicle thereby eliminating the weight and size of the twelve volt battery from the vehicle. A bank of super capacitors (18) can be included in the vehicle which are operatively connected to the PEM fuel cell auxiliary power system and to the starter.

Abstract: A fuel cell power plant includes a fuel cell having a membrane electrode assembly (MEA), disposed between an anode support plate and a cathode support plate, the anode and/or cathode support plates include a hydrophilic substrate layer having a predetermined pore size. The pressure of the reactant gas streams is greater than the pressure of the coolant stream, such that a greater percentage of the pores within the hydrophilic substrate layer contain reactant gas rather than water. Any water that forms on the cathode side of the MEA will migrate through the cathode support plate and away from the MEA. Controlling the pressure also ensures that the coolant water will continually migrate from the coolant stream toward the anode side of the MEA, thereby preventing the membrane from becoming dry. Proper pore size and a pressure differential between coolant and reactants improves the electrical efficiency of the fuel cell.

Abstract: A procedure for starting up a fuel cell system that is disconnected from its primary load and that has air in both its cathode and anode flow fields includes a) connecting an auxiliary resistive load across the cell to reduce the cell voltage; b) initiating a recirculation of the anode flow field exhaust through a recycle loop and providing a limited flow of hydrogen fuel into that recirculating exhaust; c) catalytically reacting the added fuel with oxygen present in the recirculating gases until substantially no oxygen remains within the recycle loop; disconnecting the auxiliary load; and then d) providing normal operating flow rates of fuel and air into respective anode and cathode flow fields and connecting the primary load across the cell. The catalytic reaction may take place on the anode or within a catalytic burner disposed within the recycle loop.

Abstract: A fuel cell power plant system includes the ability to operate an enthalpy recovery device even under cold conditions. A bypass arrangement allows for selectively bypassing one or more portions of the enthalpy recovery device under selected conditions. In one example, the enthalpy recovery device is completely bypassed under selected temperature conditions to allow the device to freeze and then later to be used under more favorable temperature conditions. In another example, the enthalpy recovery device is selectively bypassed during a system startup operation. One example includes a heater associated with the enthalpy recovery device. Another example includes preheating oxidant supplied to one portion of the enthalpy recovery device.

Abstract: A fuel cell power plant with enhanced water recovery includes a fuel cell power plant adapted to receive a reducing fluid and an oxidant and to generate therefrom electricity and an at least partially saturated exhaust stream; a mass and energy transfer device defining a first flow passage for the wet exhaust stream and a second flow passage for an oxidant stream, the first flow passage being in mass transfer relationship with the second flow passage; and an apparatus for cooling at least one of the oxidant stream, the exhaust stream and the mass and energy transfer device, whereby water is transferred from the exhaust stream to the oxidant stream so as to produce an at least partially saturated oxidant stream. A method is also disclosed.

Abstract: A fuel cell power plant includes a fuel cell having a membrane electrode assembly (MEA), disposed between an anode support plate and a cathode support plate, the anode and/or cathode support plates include a hydrophilic substrate layer having a predetermined pore size. The pressure of the reactant gas streams is greater than the pressure of the coolant stream, such that a greater percentage of the pores within the hydrophilic substrate layer contain reactant gas rather than water. Any water that forms on the cathode side of the MEA will migrate through the cathode support plate and away from the MEA. Controlling the pressure also ensures that the coolant water will continually migrate from the coolant stream toward the anode side of the MEA, thereby preventing the membrane from becoming dry. Proper pore size and a pressure differential between coolant and reactants improves the electrical efficiency of the fuel cell.

Abstract: A fuel cell power plant with enhanced water recovery includes a fuel cell power plant adapted to receive a reducing fluid and an oxidant and to generate therefrom electricity and an at least partially saturated exhaust stream; a mass and energy transfer device defining a first flow passage for the wet exhaust stream and a second flow passage for an oxidant stream, the first flow passage being in mass transfer relationship with the second flow passage; and an apparatus for cooling at least one of the oxidant stream, the exhaust stream and the mass and energy transfer device, whereby water is transferred from the exhaust stream to the oxidant stream so as to produce an at least partially saturated oxidant stream. A method is also disclosed.

Abstract: A procedure for starting up a fuel cell system that is disconnected from its primary load and that has air in both its cathode and anode flow fields includes a) connecting an auxiliary resistive load across the cell to reduce the cell voltage; b) initiating a recirculation of the anode flow field exhaust through a recycle loop and providing a limited flow of hydrogen fuel into that recirculating exhaust; c) catalytically reacting the added fuel with oxygen present in the recirculating gases until substantially no oxygen remains within the recycle loop; disconnecting the auxiliary load; and then d) providing normal operating flow rates of fuel and air into respective anode and cathode flow fields and connecting the primary load across the cell. The catalytic reaction may take place on the anode or within a catalytic burner disposed within the recycle loop.

Abstract: 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.

Abstract: A fuel cell with a direct antifreeze impermeable cooler plate is disclosed for producing electrical energy from reducing fluid and process oxidant reactant streams. The fuel cell includes an electrolyte secured between an anode catalyst and a cathode catalyst; an anode flow field secured adjacent the anode catalyst for directing the reducing fluid to pass adjacent the anode catalyst; a cathode flow field secured adjacent the cathode catalyst for directing the process oxidant stream to pass adjacent the cathode catalyst; a direct antifreeze impermeable cooler plate secured in heat exchange relationship with the cathode flow field; and a direct antifreeze solution passing through the cooler plate for controlling temperature within the fuel cell. The direct antifreeze solution is an organic antifreeze solution that is not volatile at cell operating temperatures.

Abstract: A direct antifreeze cooled fuel cell power plant is disclosed. The plant includes at least one fuel cell a thermal management system that directs flow of a cooling fluid for controlling heat within the plant, including a direct antifreeze solution passing through the water transport plate. The plant also integrates the direct antifreeze solution with a direct mass and heat transfer device, a water treatment system, and a steam injection system so that the direct antifreeze solution minimizes problems related to operation of the plant in sub-freezing conditions. A preferred antifreeze solution is an alkanetriol selected from the group consisting of glycerol, butanetriol, and pentanetriol. The direct antifreeze solutions minimize movement of the antifreeze as a vapor out of a water transport plate into contact with cathode or anode catalysts, and also minimize direct antifreeze solution loss from other power plant systems.

Abstract: 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.

Abstract: 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.

Abstract: An operating system for a direct antifreeze cooled fuel cell power plant is disclosed for producing electrical energy from reducing and process oxidant fluid reactant streams. The system includes at least one fuel cell for producing electrical energy from the reducing and oxidant fluid streams; fuel processing components for processing a hydrocarbon fuel into the reducing fluid; a thermal management system that directs flow of a cooling fluid for controlling heat within the plant including a porous water transport plate adjacent and in fluid communication with a cathode catalyst of the fuel cell; a direct antifreeze solution passing through the water transport plate; and, a split oxidant passage that directs the process oxidant stream into and through the fuel cell.

Abstract: Fuel Cell Having a Hydrophilic Substrate Layer A fuel cell power plant includes a fuel cell having a membrane electrode assembly (MEA), disposed between an anode support plate and a cathode support plate, the anode and/or cathode support plates include a hydrophilic substrate layer having a predetermined pore size. The pressure of the reactant gas streams is greater than the pressure of the coolant stream, such that a greater percentage of the pores within the hydrophilic substrate layer contain reactant gas rather than water. Any water that forms on the cathode side of the MEA will migrate through the cathode support plate and away from the MEA. Controlling the pressure also ensures that the coolant water will continually migrate from the coolant stream toward the anode side of the MEA, thereby preventing the membrane from becoming dry. Proper pore size and a pressure differential between coolant and reactants improves the electrical efficiency of the fuel cell.

Abstract: A direct antifreeze cooled fuel cell power plant system is disclosed for producing electrical energy from reducing and process oxidant fluid reactant streams. The system includes at least one fuel cell for producing electrical energy from the reducing and oxidant fluid streams; a thermal management system that directs flow of a cooling fluid for controlling temperature within the plant including a porous water transport plate adjacent and in direct fluid communication with a cathode catalyst of the fuel cell; a direct antifreeze solution passing through the water transport plate; and, fuel processing components secured in fluid communication with the thermal management system for processing a hydrocarbon fuel into the reducing fluid and for controlling a concentration of a direct antifreeze in the direct antifreeze solution.