Fuel cell system

A fuel cell system interconnected to a system power supply, the fuel cell system comprising:

• a fuel cell configured to generate electric power by causing a reaction between a fuel gas containing hydrogen and an oxidizing gas;
• a fuel processor including a reformer and a CO reducer, the reformer being configured to generate the fuel gas by causing a reaction between a raw material containing a hydrocarbon component and reforming water, the CO reducer being configured to reduce carbon monoxide in the fuel gas;
• a combustor configured to heat the fuel processor by combusting a combustible gas supplied to the combustor;
• a first air supply device configured to supply combustion air to the combustor;
• an electric heater configured to heat the CO reducer;
• a power supply device configured to supply electric power to the electric heater;
• a controller;
• and
• a power outage detector configured to detect a power outage in which no electric power is supplied from the system power supply to the fuel cell system, the power outage detector outputting power outage information indicative of a power outage state to the controller;
• wherein
• the controller is programmed to determine that a current state is the power outage state when the controller receives an input of the power outage information from the power outage detector before the fuel cell generates electric power,
• in the power outage state,
• the controller is programmed to at least one of:
• increasing a supply amount of the combustion air to be greater than in a power supplied state where the power outage detector does not detect the power outage;
• and decreasing a supply amount of the combustible gas to be less than in the power supplied state, and decreases an amount of heating by the electric heater to be less than in the power supplied state in a start-up step at the beginning and during start up.