Fuel cell system has controllable valve combination associated with each input and output opened to either feed fuel or oxidant or to output corresponding exhaust gases into or out of stack

摘要

The system has a number of stacked fuel cells with membrane-electrode units with intervening bipolar plates and inputs connected to a source of fuel or oxidant and outputs for the corresponding exhaust gases. A controllable valve combination (6-9) associated with each input and output is opened to either feed fuel or oxidant or to output the corresponding exhaust gases into or out of the stack (2). AN Independent claim is also included for the following: a method of operating an inventive system.