| 主权项 |
1. A solid oxide fuel cell system, in which excess fuel not used to generate electrical power flows out from one end of fuel cell units and is combusted to heat a reformer, the solid oxide fuel cell system comprising:
a fuel cell module including a plurality of fuel cell units in each of which a fuel electrode is formed on an interior passage thereof for passing the fuel therethrough; a reformer disposed inside the fuel cell module above the plurality of fuel cell units, wherein the reformer is configured to produce hydrogen and a byproduct including carbon monoxide generated from a concurrent occurrence of a partial oxidation reforming reaction caused by a chemical reaction between the fuel and reforming oxidant gas and a steam reforming reaction caused by a chemical reaction between the fuel and reforming steam; a vaporization chamber disposed above the plurality of fuel cell units and adjacent to the reformer, the vaporization chamber being configured to vaporize supplied water to produce the reforming steam; a combustion chamber disposed inside the fuel cell module below the reformer and the vaporization chamber above the fuel cell units, wherein the combustion chamber is configured to combust the fuel flowing out from the interior passage of each of the fuel cell units to heat the reformer and the vaporization chamber located above the combustion chamber; a fuel supply device configured to supply the fuel to the reformer to thereby feed the reformed fuel into each of the fuel cell units; a reforming oxidant gas supply device configured to supply the reforming oxidant gas to the reformer; a water supply device configured to supply the reforming water to the vaporization chamber; an oxidant gas supply device configured to supply oxidant gas for electrical generation to an oxidant gas electrode formed on an exterior of each of the plurality of fuel cell units; and a controller programmed to operate the fuel supply device, the oxidant gas supply device, and the water supply device during startup processes of the fuel cell module to simultaneously effect a partial oxidation reforming reaction and a steam reforming reaction in the reformer in order to heat the plurality of fuel cell units to a temperature at which generation of electrical power is possible; wherein the fuel electrode of the each fuel cell unit is comprised of a material that acts as a catalyst to effect a shift reaction in which the carbon monoxide produced as a byproduct at the reformer and the reforming steam left unused for reforming at the reformer are chemically reacted with each other at each of the fuel cell units to produce hydrogen and heat which heats up the fuel cell module; wherein the controller is programmed to operate the fuel supply device, the oxidant gas supply device and the water supply device during the startup processes of the fuel cell module so that the startup processes consist only of an AIR process and a SR process taking place sequentially in the reformer; wherein in the ATR process, the partial oxidation reforming reaction and the steam reforming reaction occur simultaneously in the reformer, and in the SR process, only the steam reforming reaction occurs in the reformer; and wherein the controller is programmed to divide the ATR into multiple sub-processes and operate the water supply device to supply water in an initial sub-process of the ATR process at a rate lower than rates at which the water is supplied in a remainder of the sub-processes of the AIR process, and further operate the fuel supply device to supply the fuel in a last sub-process at a rate lower than rates at which the fuel is supplied in all of sub-processes of the ATR process preceding to the last sub-process. |
