Solid oxide fuel cell system

摘要

A solid oxide fuel cell system is disclosed. The solid oxide fuel cell system includes a cell stack having multiple adjacent fuel cells; a reformer that reforms raw gas and produces fuel gas supplied to the fuel cells; a combustion section that causes combustion of the fuel gas discharged from the fuel cells and heats the reformer with combustion heat of the fuel gas; an ignition device that ignites the combustion section; a combustion state confirmation device that senses that heating of the entire reformer has started using the advancement of flame transfer between fuel cells in the combustion section; and a controller programmed to start an operation of the system heating the reformer by using combustion heat from the combustion section and reaction heat from the partial oxidation reforming reaction (POX) in the reformer. During the period until the combustion state confirmation device senses that the heating of the entire reformer has started after the ignition device ignited the combustion section, the controller suppresses the amount of heat emitted by the partial oxidation reforming reaction in the reformer more than the amount of heat emitted after heating of the entire reformer has started.

主权项

1. A solid oxide fuel cell system comprising:
a cell stack having adjacently arranged multiple fuel cells; a reformer configured to reform raw gas and produce fuel gas supplied to the fuel cells for generation of electricity at the fuel cells; a combustion section configured to burn residual fuel gas unused for generation of electricity and discharged from outlets of the fuel cells, wherein the reformer is heated by heat from the burning residual fuel gas in the combustion section; an ignition device configured to ignite the residual fuel gas from the outlets of the fuel cell in the combustion section, wherein upon an ignition by the ignition device, burning of the residual fuel gas begins locally over the outlets of the fuel cells and heats the reformer only locally, and then burning of the residual fuel gas progresses to spread over the entire outlets of the fuel cells and heats the reformer generally; a combustion state confirmation device configured to detect that burning of the residual fuel gas has spread over the entire outlets of the fuel cells and starts heating the reformer generally, wherein the combustion state confirmation device comprises a first temperature sensor operable to detect an inlet temperature of the reformer and a second temperature sensor operable to detect an outlet temperature of the reformer; and a controller programmed to perform a startup operation of the solid oxide fuel cell system in which the fuel cells are raised to an operation temperature at which electricity is ready to be extracted from the fuel cells, the startup operation implementing, in the reformer, a partial oxidation reforming (POX) reaction during which the reformer is heated by heat from the burning residual fuel gas in the combustion section and by reaction heat generated from the reaction taking place in the reformer, wherein the controller is further programmed to operate the solid oxide fuel cell system to: upon an ignition of the residual fuel gas by the ignition device, reduce generation of the reaction heat from the POX reaction and keep generation reduced of the reaction heat from the POX reaction while burning of the residual fuel gas undergoes locally over the outlets of the fuel cells and heats the reformer only locally; and upon a determination by the controller that the inlet and outlet temperatures of the reformer detected, respectively, by the first and second temperature sensors become no longer lower than a first and second predetermined temperature, respectively, raise, from its reduced state, generation of the reaction heat from the POX reaction, wherein the first and second predetermined temperatures are set to indicate that burning of the residual fuel gas progresses to spread over the entire outlets of the fuel cells and starts heating the reformer generally.