CASCADED STACK PROVIDED WITH GAS FLOW RECYCLING ON FIRST STEP

PROBLEM TO BE SOLVED: To provide a new and improved a gas flow recycling system in which a distribution of humidified gas flow in a fuel cell is improved. SOLUTION: A fuel cell system is provided a humidifying system in which a recycling system where a comparatively humid gas exhausted from a multi-stepped fuel cell stack is recycled on either side of an anode, cathode or both of them, and the comparatively humid gas is returned so that the gas can be mixed with comparatively dry supply gas such as, but not restricting to, hydrogen and/or air. Then, the humidified supply mixed gas are re-introduced into a first step of the multi-stepped fuel cell stack. A recycling device such as, but not restricted to, a pump and/or an ejector can help to return the humid exhausted gas to mix with the supply gas through a recycling gas line. COPYRIGHT: (C)2007,JPO&INPIT