Fuel cell system with merged gases for leak detection

A fuel cell system comprising:

• a reformer that generates a hydrogen containing gas from a fuel gas and includes a burner;
• a fuel cell that uses the hydrogen containing gas and an oxidant gas to generate power;
• an exhaust gas route for an exhaust gas discharged from the fuel cell to flow;
• an air supplier that suctions air within the fuel cell system;
• an air supply route for the air suctioned by the air supplier;
• a merging part that is a part where the exhaust gas flowing in the exhaust gas route and the suctioned air flowing in the air supply route merge with each other;
• a discharge route that discharges a mixed gas composed of the exhaust gas and the suctioned air having merged at the merging part to the atmosphere;
• a gas-liquid separator disposed on the exhaust gas route between the fuel cell and the merging part;
• and
• a combustible gas detector that is provided in the discharge route and detects concentration of a combustible gas contained in the mixed gas, wherein:
• with respect to a flow of the suctioned air flowing in the air supply route and the discharge route, from an upstream side, the air supplier, the merging part, and the combustible gas detector are disposed in this order,
• the exhaust gas includes an anode exhaust gas discharged from an anode of the fuel cell, and a cathode exhaust gas discharged from a cathode of the fuel cell,
• the exhaust gas route includes an anode exhaust gas route for the anode exhaust gas and a cathode exhaust gas route for the cathode exhaust gas,
• the burner is disposed on the anode exhaust gas route to combust the anode exhaust gas and exhaust a combustion gas,
• a condenser is disposed on the cathode exhaust gas route,
• the anode exhaust gas route downstream of the burner is connected to the cathode exhaust gas route at a position upstream of the condenser,
• the cathode exhaust gas route bypasses the burner and is connected to the condenser,
• the gas-liquid separator is a condensed water tank storing water obtained from the cathode exhaust gas and the combustion gas by the condenser, and
• the condensed water tank is connected to the reformer by a condensed water route.