Fuel cell system and start-up control method therefor

Abstract

An object is to suppress the degradation of durability due to a heat concentration while performing a rapid warm-up operation as necessary, when starting a fuel cell system at temperatures below freezing point. In order to achieve such an object, the present invention stores in a memory an operation termination condition of the last operation of the system, data such as the start-up temperature, or the remaining amount of product water at the time of the last scavenging; calculates the remaining amount of product water based on data read out from the memory at the time of starting the system to make judgments, from the remaining amount and the start-up temperature, on whether or not a rapid warm-up of the system is necessary and whether to start without circulating the cooling water when a rapid warm-up is necessary; and conducts, based on the judgment result provided by the judgment means, with or without circulating the cooling water, a low-efficiency power generation where a reactant gas to be supplied to the fuel cell is less than that in a normal power generation and an electronic power loss is larger than that in a normal power generation. The data includes, for example, an impedance, a temperature of the fuel cell and a scavenging air amount at the last termination of the operation of the fuel cell.