Patent ID: 7687162

Claim:
A purging method for a fuel cell system including a fuel cell body, a fuel reformer, a fuel supply line provided between the fuel cell body and the fuel reformer, and a purging line connected to the fuel reformer, the method comprising the steps of: subjecting the fuel reformer, the fuel cell body, and the fuel supply line to a steam purging operation such that the fuel reformer, the fuel cell body, and the fuel supply line are purged with steam to remove combustible gas; and then performing an air purging operation to remove any remaining combustible gas not removed by the steam purging operation, wherein the steam purging operation further comprises measuring a cell voltage value of the fuel cell body indicating a level of the remaining combustible gas, and before performing the air purging operation, closing a steam valve to terminate the steam purging operation, when the measured cell voltage value reaches a predetermined value indicating that the level of the combustible gas is reduced to a non-problematic safety level.