Method of improving the cold start capability of an electrochemical fuel cell

(57) Abstract: using a temperature-dependent manner, it is possible to improve the cold start capability of fuel cell power generation system. Using a method for stopping the operation of the power generation system, by reducing the amount of water remaining in the path of the stack, thereby improving the cold start capability and freeze tolerance of the fuel cell stack. The method, purged one or more of the stack oxidant and fuel passages of the fuel cell during shut down, then, to allow the temperature of the fuel cell stack is lowered to a temperature below the freezing point of water comprising the step of. Purging at shutdown is suitably carried out at a temperature lower than the stack operating temperature. Another method used on startup includes the step of directing the coolant fluid stream only to the fuel cell stack when it exceeds a pre-defined temperature higher than the freezing temperature of the water.