Solid oxide fuel cell

摘要

A solid oxide fuel cell capable of maintaining performance over a long time period by appropriately changing fuel cell module operating conditions. The present invention is a solid oxide fuel cell (1), having a fuel cell module (2), a fuel supply device (38), an oxidant gas supply device (45), and a controller (110) for controlling the amount of fuel supplied from the fuel supply device; the controller is furnished with a degradation determining circuit (110a) for determining degradation in the fuel cell module and a degradation response circuit (110b) for changing fuel cell module operating conditions based on the degradation determination by the degradation determining circuit; the degradation determination stores fuel cell module operating results arising from the operating conditions changed by the degradation response circuit, and executes further degradation determination based on the stored operating results.

主权项

1. A solid oxide fuel cell system comprising:
a fuel cell module comprising multiple fuel cell units; a fuel supply device that supplies fuel to the fuel cell module; an oxidation gas supply device that supplies oxidation gas to the fuel cell module; and a controller programed to control a fuel supply from the fuel supply device in response to a demand for electricity to control operation of the fuel cell module; wherein the controller comprises
(i) a degradation determining circuit programed to execute a degradation determination at intervals in which the degradation determining circuit obtains a measurement value regarding the operation of the fuel cell module and compares the obtained measurement value with a stored reference measurement value to determine degradation of the fuel cell module, and(ii) a degradation response circuit programed to change an operation condition for operating the fuel cell module if the degradation determining circuit determines in a last execution of the degradation determination that the fuel cell module has degraded, whereas leaving the operation condition unchanged if the degradation determining circuit determines in the last execution of the degradation determination that the fuel cell module has not degraded, wherein changing the operation condition for operating the fuel cell module comprises changing a fuel supply function which defines a relationship between the demand for electricity and the fuel supply from the fuel supply device that meets the demand for electricity; and wherein the degradation determining circuit programed to perform, if it determines in the last execution of degradation determination that the fuel cell module has degraded, a reference measurement value update in which the degradation determining circuit obtains a new measurement value while the fuel cell module is operated under the operation condition changed by the degradation response circuit, and store the new measurement value as the reference measurement value for a next execution of degradation determination, and the degradation determining circuit is further programed to dispense with performing the reference measurement value update and leave the stored reference measurement value unchanged for the next execution of degradation determination if it determines in the last execution of the degradation determination that the fuel cell module has not degraded.