Method for preventing fuel cell power plant leakage fuel gas from flowing into reformer

摘要

PURPOSE:To prevent obstacle to operation due to carbon precipitation caused by inflow of leak fuel gas into a reformer when a fuel cutoff valve is closed by providing two fuel cutoff valves in series on the fuel feeding line to the reformer, by closing the cutoff valve when the feeding of fuel is stopped, and by guiding an inert gas between the valves. CONSTITUTION:A nitrogen gas (inert gas) cutoff valve 17, a first intermediate valve 21, a first discharge gas valve 22, a second intermediate valve 24, and a second discharge gas cutoff valve 26 are fully closed while a first fuel cutoff valve 12, a second fuel cutoff valve 14, and a fourth fuel cutoff valve 15 are opened at the time of normal operation. When the feeding of fuel to a reformer 4 is to be stopped, the two valves 12, 14 are closed in a fuel feeding line 6, while the nitrogen gas is guided to the line 6 between the two valves 12 and 14, and the fuel gas leaked from the valve 12, 14 is actively discharged to the outside of a system through the line 6 between the valves 12 and 14 to a first discharge gas line 20.