Patent ID: 8114534

Claim:
A fuel cell system comprising: a fuel cell that performs power generation by an electrochemical reaction of a fuel gas and an oxidant gas; a cathode discharge pipe connected to the fuel cell that discharges oxidant offgas generated during power generation from the fuel cell; an anode drain opening in the fuel cell that discharges fuel offgas and moisture generated during power generation from the fuel cell via an anode drainpipe; a gas-liquid separator that receives the fuel offgas and the moisture from the anode drain opening via the anode drainpipe and separates fuel gas components and moisture of the fuel offgas; and a throttle valve forming an opening in a flow path of the fuel offgas between the gas-liquid separator and the cathode discharge pipe wherein the throttle valve comprises an orifice connected in series with a blocking valve; and a controller that that operates the blocking valve to restrict a flow rate of the fuel offgas, wherein a pressure difference in the anode drainpipe causes the fuel offgas and the moisture to flow from the anode drain opening to the gas-liquid separator and the fuel offgas to flow from the gas-liquid separator to the throttle valve.