Patent ID: 8652699

Claim:
A fuel cell system comprising: a fuel cell that is supplied with a reactant gas and generates electric power through an electrochemical reaction; and an exhaust pipe that discharges a reactant-off gas discharged from the fuel cell, wherein the exhaust pipe is configured to switch between a first exhaust pipe and a second exhaust pipe by means of a switching device to discharge the reactant-off gas, wherein the first exhaust pipe and the second exhaust pipe are arranged in parallel, wherein the second exhaust pipe includes a rising gradient portion formed to incline upwards above a gradient of the first exhaust pipe and a falling gradient portion formed to incline downwards at a downstream of the rising gradient portion, wherein the switching device is programmed to switch to allow the reactant-off gas to be discharged from the first exhaust pipe if an amount of reactant-off gas to be discharged is equal to or above a predetermined threshold value of an amount of discharge, and further programmed to allow the reactant-off gas to be discharged from the second exhaust pipe if the amount of reactant-off gas to be discharged is below the predetermined threshold value of the amount of discharge, and wherein the first exhaust pipe and the second exhaust pipe do not rejoin downstream of the switching device so as to prevent the reactant-off gas from the first exhaust pipe from entering the second exhaust pipe, and the reactant-off gas from the second exhaust pipe from entering the first exhaust pipe.