POWER GENERATION SYSTEM, AND METHOD FOR OPERATING SAME

A power generation system of the present invention comprises a fuel cell system (101), a gas supply device, a controller (102), a combustion device (103), an exhaust passage (70), a gas passage used to supply a gas supplied from the gas supply device to the exhaust passage (70), and a back-flow preventing device (20) placed in the gas passage or the exhaust passage (70), and the controller (102) executes an operation for relieving a state in which a valve element remains incapable of moving away from a valve seat in the back-flow preventing device (20) in such a manner that the gas supply device is operated so that a differential pressure between an upstream side and a downstream side of the back-flow preventing device (20) becomes a value equal to or greater than the predetermined time which can relieve the state in which valve element remains incapable of moving away from the valve seat, during a shut-down state or at start-up of the fuel cell system (101).