SOLID OXIDE FUEL CELL SYSTEM

摘要

To provide a solid oxide fuel cell capable of executing a shutdown stop while sufficiently suppressing fuel cell oxidation. The present invention is a solid oxide fuel cell system having a fuel cell module, a fuel supply apparatus, a water supply apparatus, a generating air supply apparatus, a reformer, a fuel/exhaust gas passageway for guiding fuel/exhaust gas from a fuel supply apparatus through a reformer to outside; and a controller comprising a shutdown stop circuit; whereby the fuel/exhaust gas passageway functions as a mechanical pressure retention means, maintaining a pressure on the oxidant gas electrode side within the fuel cell module higher than atmospheric pressure, and maintaining a pressure on the fuel electrode side at a pressure higher than the pressure on the oxidant gas electrode side, until the fuel electrode temperature drops to a predetermined oxidation suppression temperature.

主权项

1. A solid oxide fuel cell system for generating electricity by steam reforming fuel and reacting the resulting hydrogen with oxidant gas, comprising:
a fuel cell module including a fuel cell stack; a fuel supply apparatus that supplies fuel to the fuel cell module; a water supply apparatus that supplies water for steam reforming to the fuel cell module; an oxidant gas supply apparatus that supplies oxidant gas to an oxidant gas electrode side of the fuel cell stack; a reformer disposed inside the fuel cell module that performs steam reforming of fuel supplied from the fuel supply apparatus using water supplied from the water supply apparatus; a fuel/exhaust gas passageway that guides fuel/exhaust gas from the fuel supply apparatus through the reformer and fuel electrodes on fuel cell units constituting the fuel cell stack, to outside the fuel cell module; and a controller programmed to control the fuel supply apparatus, the water supply apparatus, the oxidant gas supply apparatus, and the extraction of power from the fuel cell module; wherein the controller comprises a shutdown stop circuit that executes a shutdown stop to stop the supply of fuel and the generation of electricity; and wherein the fuel/exhaust gas passageway functions as mechanical pressure retention means, maintaining a pressure on the oxidant gas electrode side within the fuel cell module higher than atmospheric pressure, and maintaining a pressure on the fuel electrode side at a pressure higher than the pressure on the oxidant gas electrode side, after the shutdown stop circuit executes the shutdown stop, until a temperature of the fuel electrodes drop to a predetermined oxidation suppression temperature at which the risk of fuel electrode oxidation is diminished.