Abstract: An apparatus (10) configured to determine reactant purity comprising: a first fuel cell (11) configured to generate electrical current from the electrochemical reaction between two reactants, having a first reactant inlet (13) configured to receive a test reactant comprising one of the two reactants from a first reactant source (7, 5, 16); a second fuel cell (12) configured to generate electrical current from the electrochemical reaction between the two reactants, having a second reactant inlet (14) configured to receive the test reactant from a second reactant source (5); a controller (20) configured to apply an electrical load to each fuel cell and determine an electrical output difference, ODt, between an electrical output of the first fuel cell (11) and an electrical output of the second fuel cell (12), and determine a difference between a predicted output difference and the determined electrical output difference, ODt, the predicted output difference determined based on a historical output of difference

Abstract: An apparatus (10) configured to determine reactant purity comprising: a first fuel cell (11) configured to generate electrical current from the electrochemical reaction between two reactants, having a first reactant inlet (13) configured to receive a test reactant comprising one of the two reactants from a first reactant source (7, 5, 16); a second fuel cell (12) configured to generate electrical current from the electrochemical reaction between the two reactants, having a second reactant inlet (14) configured to receive the test reactant from a second reactant source (5); a controller (20) configured to apply an electrical load to each fuel cell and determine an electrical output difference, ODt, between an electrical output of the first fuel cell (11) and an electrical output of the second fuel cell (12), and determine a difference between a predicted output difference and the determined electrical output difference, ODt, the predicted output difference determined based on a historical output of difference

Abstract: An apparatus (10) configured to determine reactant purity comprising: a first fuel cell (11) configured to generate electrical current from the electrochemical reaction between two reactants, having a first reactant inlet (13) configured to receive a test reactant comprising one of the two reactants from a first reactant source (7, 5, 16); a second fuel cell (12) configured to generate electrical current from the electrochemical reaction between the two reactants, having a second reactant inlet (14) configured to receive the test reactant from a second reactant source (5); a controller (20) configured to apply an electrical load to each fuel cell and determine an electrical output difference, ODt, between an electrical output of the first fuel cell (11) and an electrical output of the second fuel cell (12), and determine a difference between a predicted output difference and the determined electrical output difference, ODt, the predicted output difference determined based on a historical output of difference

Abstract: A fuel cell stack assembly has a plurality of cells each having a fluid coolant conduit. A coolant feed manifold has a first inlet and a second inlet and is coupled to each fluid coolant conduit for distribution of fluid coolant within each cell. A pump is coupled for delivery of fluid coolant to the coolant feed manifold through the first and second inlets. A flow control assembly is configured to periodically modify the relative flow rates of fluid coolant through the first and second inlets so that stagnant regions in the coolant feed manifold are avoided. The flow control assembly may also be adapted to periodically interrupt the flow path between the pump and the manifold such that the fluid coolant is delivered to the manifold intermittently, thereby enabling low water flows below a minimum set point of the pump.

Abstract: A pair of fuel cells are configured as a hydrogen purity monitor. A first cell, acting as a reference cell, is configured to generate electrical current from the electrochemical reaction of hydrogen and oxidant and has a first fuel inlet configured to receive hydrogen from a first hydrogen source. A second fuel cell, acting as a test cell, is configured to generate electrical current from the electrochemical reaction of hydrogen and oxidant and has a second fuel inlet configured to receive hydrogen from a second hydrogen source. A control system is configured to apply an electrical load to each fuel cell and determine an electrical output of each fuel cell. The control system has a comparator for comparing the electrical outputs of the first and second fuel cells and a purity monitor output configured to give an indication of hydrogen purity based on an output of the comparator.

Abstract: An apparatus (10) configured to determine reactant purity comprising: a first fuel cell (11) configured to generate electrical current from the electrochemical reaction between two reactants, having a first reactant inlet (13) configured to receive a test reactant comprising one of the two reactants from a first reactant source (7, 5, 16); a second fuel cell (12) configured to generate electrical current from the electrochemical reaction between the two reactants, having a second reactant inlet (14) configured to receive the test reactant from a second reactant source (5); a controller (20) configured to apply an electrical load to each fuel cell and determine an electrical output difference, ODt, between an electrical output of the first fuel cell (11) and an electrical output of the second fuel cell (12), and determine a difference between a predicted output difference and the determined electrical output difference, ODt, the predicted output difference determined based on a historical output of difference

Abstract: A fuel cell (FC) system operating as its own hydrogen leak detector. The system including at least one cathode and cathode conduit for passage of oxidant to the cathode and a housing containing one or more FCs and defining a plenum around the FC. A ventilation system forces air from the plenum into the cathode conduit and a control system monitors the FC voltage and detects a drop in voltage attributable to hydrogen in the cathode conduit. A control system may include actual cell voltage monitoring of the FC or of one or more cells in the FC stack and a processor for receiving inputs indicative of the operation of the FC or FC stack and/or to determine an expected voltage of FC(s) being monitored and whether the difference between the actual and expected voltage(s) exceeds a predetermined threshold indicative of a predetermined level of hydrogen in the cathode conduit.

Abstract: A fuel cell stack assembly has a plurality of fuel cells each having a fluid coolant conduit. A coolant feed inlet manifold has a coolant inlet, and the coolant feed inlet manifold is coupled to each fluid coolant conduit for distribution of coolant to each fuel cell. The coolant feed inlet manifold also has a discharge conduit located at one end of the coolant feed inlet manifold. The discharge conduit is configured to discharge excess coolant from the coolant feed inlet manifold. By supplying excess coolant to the coolant feed inlet manifold problems arising due to very low coolant flow rates through the fluid coolant conduits in the fuel cells can be reduced or eliminated.

Abstract: A pair of fuel cells are configured as a hydrogen purity monitor. A first cell, acting as a reference cell, is configured to generate electrical current from the electrochemical reaction of hydrogen and oxidant and has a first fuel inlet configured to receive hydrogen from a first hydrogen source. A second fuel cell, acting as a test cell, is configured to generate electrical current from the electrochemical reaction of hydrogen and oxidant and has a second fuel inlet configured to receive hydrogen from a second hydrogen source. A control system is configured to apply an electrical load to each fuel cell and determine an electrical output of each fuel cell. The control system has a comparator for comparing the electrical outputs of the first and second fuel cells and a purity monitor output configured to give an indication of hydrogen purity based on an output of the comparator.

Abstract: A fuel cell stack assembly has a plurality of fuel cells each having a fluid coolant conduit. A coolant feed inlet manifold has a coolant inlet, and the coolant feed inlet manifold is coupled to each fluid coolant conduit for distribution of coolant to each fuel cell. The coolant feed inlet manifold also has a discharge conduit located at one end of the coolant feed inlet manifold. The discharge conduit is configured to discharge excess coolant from the coolant feed inlet manifold. By supplying excess coolant to the coolant feed inlet manifold problems arising due to very low coolant flow rates through the fluid coolant conduits in the fuel cells can be reduced or eliminated.

Abstract: A fuel cell stack assembly has a plurality of cells each having a fluid coolant conduit. A coolant feed manifold has a first inlet and a second inlet and is coupled to each fluid coolant conduit for distribution of fluid coolant within each cell. A pump is coupled for delivery of fluid coolant to the coolant feed manifold through the first and second inlets. A flow control assembly is configured to periodically modify the relative flow rates of fluid coolant through the first and second inlets so that stagnant regions in the coolant feed manifold are avoided. The flow control assembly may also be adapted to periodically interrupt the flow path between the pump and the manifold such that the fluid coolant is delivered to the manifold intermittently, thereby enabling low water flows below a minimum set point of the pump.

Abstract: A fuel cell (FC) system operating as its own hydrogen leak detector. The system including at least one cathode and cathode conduit for passage of oxidant to to the cathode and a housing containing one or more FCs and defining a plenum around the FC. A ventilation system forces air from the plenum into the cathode conduit and a control system monitors the FC voltage and detects a drop in voltage attributable to hydrogen in the cathode conduit. A control system may include actual cell voltage monitoring of the FC or of one or more cells in the FC stack and a processor for receiving inputs indicative of the operation of the FC or FC stack and/or to determine an expected voltage of FC(s) being monitored and whether the difference between the actual and expected voltage(s) exceeds a predetermined threshold indicative of a predetermined level of hydrogen in the cathode conduit.

Abstract: A gasket for sealing internal surfaces of a fuel cell and formed of compressible material, the gasket comprising a first sealing surface and a second sealing surface for providing a fluid seal against opposing faces of a first fluid flow field plate and a second fluid flow field plate respectively, the gasket further comprising a third sealing surface for sealing against an outer perimeter region of a first surface of a membrane electrode assembly, the third sealing surface being entirely enclosed within a boundary defined by an inner perimeter of the second sealing surface.

Abstract: An electrochemical fuel cell having an anode, an ion transfer membrane and a cathode has liquid water delivered to the fluid flow channels within the cathode so as to maintain a relative humidity of 100% throughout the fluid flow channels. A calibration method and apparatus is described for determining an optimum quantity or range of quantities of liquid water to be delivered to the cathode fluid flow channels under varying operating conditions. An operating method and apparatus is described that ensures an optimum quantity of liquid water is delivered to the cathode fluid flow channels under varying operating conditions.

Abstract: A gasket for sealing internal surfaces of a fuel cell and formed of compressible material, the gasket comprising a first sealing surface and a second sealing surface for providing a fluid seal against opposing faces of a first fluid flow field plate and a second fluid flow field plate respectively, the gasket further comprising a third sealing surface for sealing against an outer perimeter region of a first surface of a membrane electrode assembly, the third sealing surface being entirely enclosed within a boundary defined by an inner perimeter of the second sealing surface.

Abstract: An electrochemical fuel cell having an anode, an ion transfer membrane and a cathode has liquid water delivered to the fluid flow channels within the cathode so as to maintain a relative humidity of 100% throughout the fluid flow channels. A calibration method and apparatus is described for determining an optimum quantity or range of quantities of liquid water to be delivered to the cathode fluid flow channels under varying operating conditions. An operating method and apparatus is described that ensures an optimum quantity of liquid water is delivered to the cathode fluid flow channels under varying operating conditions.

Abstract: There is disclosed an electrolytic or fuel cell arrangement comprising a stacking of bipolar elements (21, 31, 41), each element comprising an anode part (22) and a cathode part (23), the anode part of one element cooperating with the cathode part of the next adjacent element.