To provide a fuel battery system that can effectively protect a fuel battery from thermal shock in a subzero step-up of the fuel battery.
The fuel battery system includes: a fuel battery that generates electricity by receiving a supply of a reactive gas; a circulation flow path that recovers a cooling medium having passed inside of the fuel battery and agian introducing the cooling medium in the fuel battery; and a circulation device that circulates the cooling medium into the fuel battery via the circulation flow path, and repeatedly and alternatively executes a heat operation that generates the fuel battery power while the circulation device is being stopped, and a circulation movement that drives the circulation device that circulates the cooling medium into the fuel battery via the circulation flow path when the fuel battery is started below zero, wherein when the amount of heat value generated by the fuel battery reaches a predetermined target heat value, switching from heat operation to circulation operation is executed, and moreover, when the fuel battery and the cooling medium reaches thermal balance while the circulation operation is being executed, the circulation operation is switched to the heat operation.
HAMANOI OSAMU
Mamoru Takada
Hidekazu Onishi