Fuel cell system and operation method for fuel cell system

A fuel cell system comprising:

• a fuel cell;
• a fuel gas supply portion;
• a fuel gas supply channel that supplies a fuel gas from the fuel gas supply portion to the fuel cell;
• a fuel gas circulation channel that is connected to the fuel cell and to the fuel gas supply channel and that circulates the fuel gas discharged from the fuel cell by returning the fuel gas to the fuel gas supply channel for reuse;
• a circulation pump provided on the fuel gas circulation channel so as to circulate the fuel gas;
• a temperature detection portion that detects a temperature of the fuel cell system;
• a pump control portion that drives the circulation pump;
• and
• a breakdown determination portion that determines whether the circulation pump has a breakdown,
• wherein the breakdown determination portion determines that the circulation pump has a the breakdown if the temperature of the fuel cell system detected by the temperature detection portion is higher than or equal to a melting point of water and a rotation speed of the circulation pump driven by the pump control portion is less than a predetermined rotation speed.

An operation method for a fuel cell system including a fuel cell, a fuel gas supply portion, a fuel gas supply channel that supplies a fuel gas from the fuel gas supply portion to the fuel cell, a fuel gas circulation channel that is connected to the fuel cell and to the fuel gas supply channel and that circulates the fuel gas discharged from the fuel cell to the fuel gas supply channel for reuse, and a circulation pump provided on the fuel gas circulation channel so as to circulate the fuel gas, the operation method comprising:

• detecting a temperature of the fuel cell system when the fuel cell system is started;
• warming the circulation pump if the detected temperature of the fuel cell system is less than a melting point of water;
• driving the circulation pump;
• and
• determining that the circulation pump has broken if the temperature of the fuel cell system is higher than or equal to the melting point of water and a rotation speed of the circulation pump is less than a predetermined rotation speed.