Solid oxide fuel cell device

摘要

A solid oxide fuel cell device is provided which prevents excessive rising of the temperature inside a fuel cell module during the startup process. In a startup process, control unit controls to cause a transition from a fuel gas reforming reaction process to a POX process, an ATR process, and a SR process, then to a generating process; when the cell stack temperature and reformer temperature in each process satisfy respectively set transition conditions, a transition to the next process takes place; if control unit determines a temperature rise assist state exists, it executes an excess temperature rise suppression control so that during at least the transition to the generating process, the reformer temperature does not exceed a predetermined value.

主权项

1. A solid oxide fuel cell system, comprising:
a cell stack including a stack of multiple fuel cell units disposed in a power generation chamber; a reformer configured to reform fuel gas and supply the reformed fuel gas to the fuel cell units; a combustion portion configured to heat the reformer and the cell stack with exhaust gas resulting from combustion of surplus fuel gas or the reformed fuel gas passed through the fuel cell units; a first temperature detector configured to detect a temperature of the power generating chamber representative of a temperature of the cell stack; a second temperature detector configured to detect a temperature of the reformer; a module housing chamber for housing the cell stack and the reformer; a heat storage means disposed around the module housing chamber; a determining means for determining whether a temperature rise assist state occurs in which a temperature rise in the reformer and/or cell stack is assisted by the heat amount stored by the heat storage means during startup of the fuel cell system; and a controller programmed to start up the fuel cell system; wherein the controller is programmed so that in the fuel cell system startup process, supply flow rates of fuel gas, oxidant gas, and steam supplied to the reformer are controlled based on the cell stack temperature and the reformer temperature, and after a fuel gas reformer reaction process including a plurality of processes performed by reformer, a transition is made from a steam reforming reaction process (SR process) in the fuel gas reformer reaction process to a generating process, and when the cell stack temperature and the reformer temperature satisfy transition conditions set to each of the plurality of processes in the fuel gas reformer reaction process, a transition is made to a next process; and wherein if the determining means determines an occurrence of a state where one of the temperatures of the reformer and the cell stack reaches a predetermined temperature which is higher than its transition condition temperature, while the other does not reach its transition condition temperature or when the two temperatures reach their transition condition temperature, the controller performs an excess temperature rise suppression control to prevent the reformer temperature from rising to or above a predetermined value, at least at the time of transition to the generating process.