Abstract: A coolant injection controller for a fuel cell system, the coolant injection controller configured to actively control the flow of a coolant to a fuel cell assembly for cooling and/or hydrating the fuel cell assembly in response to a measure of fuel cell assembly performance, wherein the coolant injection controller is configured to provide for a first mode of operation if the measure of fuel cell assembly performance is below a predetermined threshold and a second mode of operation if the measure of fuel cell assembly performance is above the predetermined threshold, the first and second modes having different coolant injection profiles and wherein, in the first mode of operation, the coolant injection profile provides for control of the flow of coolant by alternating between at least two different injection flow rates.

Abstract: An electrochemical fuel cell assembly comprises a fuel cell stack having a fuel delivery inlet and a fuel delivery outlet. The fuel cell stack further includes a number of fuel cells each having a membrane-electrode assembly and a fluid flow path coupled between the fuel delivery inlet and the fuel delivery outlet for delivery of fuel to the membrane-electrode assembly. A fuel delivery conduit is coupled to the fuel delivery inlet for delivery of fluid fuel to the stack. A bleed conduit is coupled to the fuel delivery outlet for venting fluid out of the stack. A variable orifice flow control device coupled to the bleed conduit configured to dynamically vary an amount of fluid from the fuel delivery outlet passing into the bleed conduit as a function of one or more of the control parameters: (i) measured fuel concentration; (ii) measured humidity; (iii) cell voltages of fuel cells in the stack; (iv) impedance of fuel cells in the stack; (v) resistance of fuel cells in the stack.

Abstract: A fuel cell system comprising a fuel cell stack is disclosed. An ozone generator is configured to introduce ozone into a coolant in the fuel cell system. A deionisation apparatus is coupled to the fuel cell stack. A bypass conduit is arranged in parallel with the deionisation apparatus. A controller is configured to control flow of the coolant to the fuel cell stack through either the deionisation apparatus or the bypass conduit based on the operating state of the ozone generator.

Abstract: A fuel cell system comprises an antimicrobial patterned surface. The fuel cell system may comprise a fuel cell stack, a coolant reservoir, and a coolant flow path configured to supply coolant from the coolant reservoir to the fuel cell stack. One or more of the fuel cell stack, the coolant reservoir and the coolant flow path may comprise the antimicrobial patterned surface.

Abstract: A liquid separator (100) comprising: an inlet (102) configured to receive a fluid flow; an outlet (104); and a separation chamber (106) defining a fluid flow path between the inlet (102) and the outlet (104), wherein the separation chamber (106) comprises an aerofoil (108) in the fluid flow path configured to separate liquid out of the fluid flow at regions of reduced fluid pressure.

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.