Patent ID: 8530104
Filing Date: 2013-09-10
Classification: H01M,Y02E

Abstract:
1. A method of operating a fuel cell system, the method comprising steps of: (a) stopping power generation of a fuel cell which generates electric power using a fuel gas and an oxidizing gas; (b) filling a cathode of the fuel cell with a combustible gas in a stop operation of the fuel cell system after step (a) and keeping the filled combustible gas in the cathode until starting a start-up operation of the fuel cell system; (c) supplying the oxidizing gas to the cathode and discharging the combustible gas filled in the cathode with the oxidizing gas after step (b); (d) supplying the combustible gas discharged from the cathode in response to step (c) to a combustor configured to heat a fuel generator for generating the fuel gas or to an exhaust pipe connected to the combustor via a branch passage branching from an oxidizing gas passage located downstream of the cathode; (e) diluting the combustible gas supplied to the combustor with air supplied to the combustor or the combustible gas supplied to the exhaust pipe with exhaust gas supplied to the exhaust pipe, such that the combustible gas has a concentration lower than a combustion lower limit; and (f) discharging the diluted combustible gas to atmosphere.