Toto Ltd.

Kiyotaka Nakano

Katsuhisa Tsuchiya

Toshiharu Ooe

Tsukasa Shigezumi

Toshiharu Otsuka

Yoshiyuki Kawamura

Takuya Matsuo

The present invention provides a solid oxide fuel cell system capable of preventing excess temperature rises while increasing overall energy efficiency. The present invention is a solid oxide fuel cell system, including: a fuel cell module, a fuel supply device, a heat storing material, and a controller which, based on power demand, increases the fuel utilization rate when output power is high and to lower it when output power is low, and changes the electrical power actually output at a delay after changing the fuel supply amount. The controller has a stored heat estimating circuit for estimating the surplus heat based on fuel supply and on power output at a delay relative thereto. When a utilizable amount of surplus heat is accumulated in the heat storage material, the fuel supply is reduced so that the fuel utilization rate increases relative to the same electrical power.

Solid oxide fuel cell system for producing variable generated power based on power demand

The present invention is to provide a solid oxide fuel cell capable of improving the overall energy efficiency. The present invention is directed to a solid oxide fuel cell and comprising: a fuel cell module; a fuel supply device; a combustion chamber for burning excess fuel and heating; a heat storing material, a power demand detecting sensor; a temperature detection device, and a control device for controlling so that the fuel utilization rate is high when generated power is large, and also for changing output power at a delay to the fuel supply rate; whereby the control device comprises a stored heat amount estimating circuit, and when it is estimated that a utilizable heat amount has accumulated in the heat storing material, the fuel supply rate is reduced so that the fuel utilization rate increases vs. the same generated power.

The invention is to provide a solid oxide fuel cell system including: a fuel cell module, a fuel flow regulator unit, a first power demand detection device, a control section for controlling a fuel supply amount and setting the current value extractable from the fuel cell module, an inverter for extracting current in a range not exceeding the extractable current value, and a power state detecting sensor for detecting actual extracted current value; whereby if actual extracted current value declines, then under circumstances where power demand begins to rise in a state of extra margin in the fuel supply amount after the controller suddenly decreases the extractable current value and suddenly reduces the electrical collector, the controller increases the extractable current value at a high current rise rate of change.

Solid oxide fuel cell system

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.

To provide a solid oxide fuel cell system capable of efficiently and simply controlling a low speed fuel cell module and a high speed inverter. The invention is a solid oxide fuel cell system, comprising: a fuel cell module, a fuel flow regulator unit, a control section comprising a first power demand detection circuit for controlling the fuel supply amount and for setting the value of current extractable from the fuel cell module; an inverter for extracting current from fuel cell module; and a second power demand detection circuit; and having an inverter control section for controlling the inverter independently from the fuel cell controller so that a current responsive to power demand is extracted from the fuel cell module in a range not exceeding the extractable current value input from the fuel cell controller.

To provide a solid oxide fuel cell device capable of smooth transition from a startup state to an electrical generating state. The present invention is a solid oxide fuel cell device () for generating electricity, having a fuel cell module (); a reformer (), a fuel supply device (); a water supply device (), a generating oxidant gas supply device (), and a controller () for controlling the fuel supply device and water supply device at the time of startup when the fuel cell module solid oxide fuel cell unit is raised to a temperature at which electrical generation is possible; whereby the controller controls the fuel supply device during the SR operation such that electrical generation is started after reducing the fuel supply flow rate prior to starting electrical generation.

Solid oxide fuel cell device

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.

To provide a solid oxide fuel cell device for preventing excess temperature rises inside a fuel cell module during the startup process. During a startup process, a control unit controls the supplied amounts of fuel gas, oxidant gas, and steam supplied to a reformer based on cell stack temperature and reformer temperature and causes transition to a generating process after transitioning to a POX process, an ATR process, and a SR process, and controls to cause a transition to the next process if in each process the cell stack temperature and reformer temperature meet transition conditions set for each; when control unit determines a temperature rise assist state, it controls to cause a transition to the generating process in a state of reduced fuel gas supply amounts compared to when it does not determine a temperature rise assist state.

The SOFC of the present invention has a plurality of individual solid oxide fuel cells () disposed within an generating chamber (), a fuel supply unit () for supplying fuel to the individual solid oxide fuel cells, a temperature sensor () for measuring the temperature of the generating chamber (T), and a control section () for changing the amount of fuel supplied in response to an amount of generation required based on control characteristics for supplying fuel, wherein the control section is furnished with a temperature band for monitoring purposes, having a minimum temperature value (Ta) and a maximum temperature value (Tb) for adaptive control, predetermined based on a minimum amount and maximum amount of rated electrical generation, and a maximum temperature value for adaptive control in response to anomalies, which is higher than the maximum temperature value (Tb) of the adaptive control temperature band, and a minimum temperature value for adaptive control in response to anomalies, which is lower than the minimum temperature value (Ta) of the adaptive control temperature band, and the control section is furnished with: an anomaly response control section for executing anomaly response control by restricting operation of the fuel cell when the generating chamber temperature (T) is higher than the maximum temperature value for anomaly response control or lower than the minimum temperature value for anomaly response control, and with an adaptive control section for executing adaptive control by correcting the amount of fuel supplied based on a temperature signal from the temperature measurement sensor so that the generating chamber temperature (T) is kept within the temperature band when the generating chamber temperature (T) exceeds the minimum temperature value (Ta) or maximum temperature (Tb) for adaptive control and goes outside the temperature band.

A solid oxide fuel cell is provided with which the further advance of degradation can be restrained relative to fuel cell units in which degradation has advanced. The present invention is a solid oxide fuel cell system which varies output power in response to a required generation amount. The system comprises a fuel cell module furnished with multiple fuel cell units, a fuel supply device for supplying fuel to the fuel cell module, an oxidant gas supply device for supplying oxidant gas to the fuel cell module, and a controller for changing the amount of fuel supplied from the fuel supply means in response to the required generation amount. The controller reduces the rate of change in the fuel supply amount per unit time when the required generation amount changes subsequent to an estimate or determination that the fuel cell module has degraded.

Solid oxide fuel cell

The present invention comprises a fuel cell assembly, a reformer, a fuel flow rate regulator unit for supplying fuel gas to the reformer, a reforming air supply device, a power generating air supply device, and a control unit for igniting fuel gas using an ignition device and conducting a combustion operation causing the fuel gas to combust using power generating air, then sequentially implementing a POX operation, ATR operation, and SR operation; whereby the control section starts the supply of fuel gas, reforming air, and power generating air, then controls the fuel gas supply device, the reforming air supply device, and the power generating air supply device to hold constant the respective supply flow rates of fuel gas, reforming air, and power generating air, without variation, in the combustion operating region in which fuel gas is ignited by the ignition device and combusted.

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 (), having a fuel cell module (), a fuel supply device (), an oxidant gas supply device (), and a controller () for controlling the amount of fuel supplied from the fuel supply device; the controller is furnished with a degradation determining circuit () for determining degradation in the fuel cell module and a degradation response circuit () 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.

To provide a solid oxide fuel cell device capable of smooth transition from a startup state to an electrical generating state. The present invention is a solid oxide fuel cell device () for generating electricity, having a fuel cell module (); a reformer (), a fuel supply device (); a water supply device (), a generating oxidant gas supply device (), and a controller () for controlling the fuel supply device and water supply device at the time of startup when the fuel cell module solid oxide fuel cell unit is raised to a temperature at which electrical generation is possible, inducing in the reformer a SR in which only a steam reforming reaction occurs; wherein the control section maintains the fuel supply flow rate in the SR immediately prior to electrical generation at an electrical generation standby fuel supply flow rate determined according to solid oxide fuel module usage conditions and smaller than the fuel supply flow rate at the time of SR startup.

To provide a solid oxide fuel cell capable of extending the time period over which a minimum rated output power can be maintained while restraining the advance of fuel cell module degradation. The present invention is a solid oxide fuel cell (), having a fuel cell module (), a fuel supply device (), an oxidant gas supply device (), and a controller (); wherein the controller is furnished with a degradation determining circuit for determining degradation () and a fuel correction circuit for correcting operating condition (); in which the fuel correction circuit executes a correction to reduce rated output power so that the fuel supply amount is reduced when a determination is made that the fuel cell module has degraded, and when degradation of the fuel cell module advances and predetermined correction switching condition is satisfied, the fuel correction circuit corrects the fuel supply amount supplied to the fuel cell module so as to maintain the reduced rated output power.

A fuel cell system includes a fuel cell module having a solid-oxide fuel cell and a reformer adapted to perform steam reforming of a fuel gas supplied to the solid-oxide fuel cell, a water supplying unit and a control unit. The controller unit is adapted to control, at least during start up of the fuel cell system switching of a pulse pump from a stop state to a pumping state to start pumping of water, and to change the pulse pump to a normal control state after performing a start-operation-control which sets a feed flow rate of the pulse pump higher for a predetermined time than a feed flow rate of the water during the normal control state.

Growing community of inventors

Kitakyushu, Japan

Kiyotaka Nakano