US Patent 7122259 Fuel cell startup method

Ice in a fuel cell (1) is thawed by passing a hot gas flow in a fuel gas passage, oxidizing agent gas passage and cooling liquid passage in the fuel cell (1), and the fuel cell (1) is started from a low temperature state. When startup processing begins, a gas flow comprising dry, hot gas in which there is no water or effectively no water is passed through the fuel cell (1), and subsequently, a steam amount contained in the gas flow is increased according to the temperature rise of the fuel cell (1).