Abstract: A bipolar plate for a four-fluid fuel cell includes a nonporous sub-plate and a porous sub-plate. The nonporous sub-plate includes a water management side, an opposing reactant side, and an internal coolant passage therebetween. The porous sub-plate includes a reactant side and an opposing water management side. The reactant side includes a first reactant flow field, and the water management side is fluidly connected to the water management side of the nonporous sub-plate. Embodiments of the invention include a method to operate the four-fluid fuel cell in thermal boost mode, and a method to accumulate and retain product water.

Abstract: A vehicle includes a fuel cell, an inlet valve, a purge valve, and a controller. The fuel cell has an anode side configured to receive hydrogen. The inlet valve is configured to open to deliver the hydrogen to the anode side. The purge valve is configured to open to purge water and nitrogen from the anode side. The controller is programmed to, operate the inlet valve to inject hydrogen into the anode side via opening the inlet valve followed by closing the inlet valve. The controller is further programmed to, in response to a concentration of the hydrogen in the anode side being less than threshold, open the purge valve to purge water and nitrogen from the anode side.

Abstract: A fuel cell system includes a fuel cell, first and second supply devices, a gas-liquid separator, a discharge valve, first and second ejectors for discharging fuel gas and off gas to the fuel cell, a measuring device for gas pressure, and a control device. The first ejector has a discharge amount smaller than the second ejector. The first ejector has a circulation amount larger than the second ejector. The control device executes the supply during a first time from the first supply device at each first cycle such that the pressure becomes a first target value, and when the first ejector is in an abnormal state, stops the first supply device, executes the supply during a shorter second time from the second supply device at each shorter second cycle such that the pressure becomes a higher second target value, and opens and closes the discharge valve at each first cycle.

Abstract: Provided is a low-cost electrochemical element that includes a high-performance electrode layer. The electrochemical element includes an electrode layer, and the electrode layer contains small particles and large particles. The small particles have a particle diameter of 200 nm or less in the electrode layer, and the large particles have a particle diameter of 500 nm or more in the electrode layer.

Abstract: A method for purging the hydrogen feed anode circuit of a fuel cell, whereby hydrogen is fed at a nominal pressure to the inlet of the cell, characterized in that at predetermined periodicity the following steps are repeated: instruction is given to open the hydrogen purge valve arranged on the outlet of the anode circuit; the pressure of hydrogen is measured at the inlet to the anode circuit of the cell, and the measured value is compared with a predetermined threshold pressure value; and the purge valve is closed when the measured pressure is equal to or lower than the predetermined threshold pressure value.

Abstract: A method of detecting degradation of a membrane electrode assembly of a fuel cell is provided. In the method, it is possible to detect degradation (cross leakage) of the fuel cell. In the measurement step, the pressure drop value of the pressure of the fuel gas which decreases in the power generation state after discharging of the predetermined amount of the fuel gas, in each predetermined period of time is measured a plurality of times. Thereafter, in the determination step, it is determined that the membrane electrode assembly has been degraded in the case where the minimum pressure drop value, among a plurality of pressure measurement values, exceeds a threshold value.

Abstract: A fuel battery system includes: a plurality of fuel tanks configured to store fuel; a fuel battery stack configured to generate electricity using the fuel supplied from each of the plurality of fuel tanks; a filling unit configured to fill each of the plurality of fuel tanks with the fuel; and a control device configured to control the fuel battery stack to maintain generating of electricity by continuously supplying fuel from at least any one of the plurality of fuel tanks other than the fuel tank filled with the fuel from the filling unit to the fuel battery stack when at least one of the plurality of fuel tanks is filled with the fuel from the filling unit.

Abstract: The invention relates to a bipolar separator (17) including a first (33) and a second (35) polar plate each comprising an inner surface and an outer surface in which at least one distribution channel (53, 55) is formed, the channels formed in the outer surfaces of the first and the second polar plate enabling fuel and oxidizer, respectively, to flow. The bipolar separator further includes an inner layer (29) provided to be sandwiched and compressed between the substantially planar inner surfaces of the first (33) and the second (35) polar plate, so as to form a laminated structure. The inner layer is formed by a perforated sheet comprising a group of through-grooves that form branchless channels, the ends of which lead, respectively, to two manifolds such that the coolant is able to flow between the first (33) and the second (35) polar plate.

Abstract: A method for supplying at least one fuel cell of a fuel cell system of the motor vehicle with fuel includes ascertaining or predicting an indication value which is indicative of the real and/or possible mass flow of the withdrawal of fuel from a pressure-vessel system of the motor vehicle and closing at least one tank shut-off valve when the indication value is equal to or falls below a limiting value.

Abstract: A heat exchanger for cooling multiple rows of battery cells has a plurality of longitudinal flow sections defining at least first and second U-shaped flow areas, each underlying a row of battery cells. The flow sections includes inlet and outlet flow sections, and at least two intermediate flow sections. Inlet and outlet ports are in flow communication with the respective inlet and outlet flow sections, and a first bypass channel extends between the inlet port and at least one of the intermediate flow sections. The first bypass channel supplies relatively cold heat transfer fluid from the inlet to mix with warmer fluid in a second or subsequent U-shaped flow area, to improve temperature uniformity between the rows of battery cells. A second bypass channel may extend around the outer periphery of the heat exchanger, from the inlet flow section to a second or subsequent U-shaped flow area.

Abstract: Surface conduction in porous media can drastically alter the stability and morphology of electrodeposition at high rates, above the diffusion-limited current. Above the limiting current, surface conduction inhibits growth in the positive membrane and produces irregular dendrites, while it enhances growth and suppresses dendrites behind a deionization shock in the negative membrane. The discovery of uniform growth contradicts quasi-steady “leaky membrane” models, which are in the same universality class as unstable Laplacian growth, and indicates the importance of transient electro-diffusion or electro-osmotic dispersion. Shock electrodeposition could be exploited for high-rate recharging of metal batteries or manufacturing of metal matrix composite coatings.

Abstract: A fuel tank for storing a hydrogen liquid carrier and a spent hydrogen liquid carrier includes a substantially rigid exterior tank wall including a first chamber and a second chamber. The first chamber is fluidly disconnected from the second chamber, and the second chamber includes a dynamically expandable and contractible enclosure, the enclosure being configured to define a dynamic boundary between the hydrogen liquid carrier and spent hydrogen liquid carrier. The fuel tank also includes a first channel in flow communication with one of the first chamber or the second chamber and a second channel in flow communication with another of the first chamber or the second chamber, wherein the first channel and the second channel are flow connected such that a flow through one of the first or second channels is returned to the another of the first or second channels, and that during the flow, the dynamic boundary changes position causing a change in a volume of the second chamber.

Abstract: A fuel cell system includes: a turbine including a changing mechanism that adjusts a pressure difference between an upstream pressure and a downstream pressure of the turbine, the turbine recovering at least a part of energy of the cathode off-gas using the pressure difference and assisting driving of the motor with the recovered energy; and a control unit configured to drive the changing mechanism to increase or decrease the recovered energy. The control unit acquires a correlation temperature correlated with a temperature of the cathode off-gas discharged from the turbine and performs freezing avoidance control of not setting the degree of opening to be equal to or less than a predetermined degree of opening when the correlation temperature is lower than a predetermined threshold temperature at which the turbine is able to become frozen.

Abstract: A system for determining a battery condition includes a temperature sensor configured to provide a temperature value associated with the battery, an impedance sensor configured to provide impedance information associated with the battery, and a controller. The controller is configured to determine a threshold impedance associated with a separator membrane of the battery based on an initial impedance of the separator membrane as measured by the impedance sensor and a battery temperature as measured by the temperature sensor, monitor, during operation of the battery, an actual impedance associated with the separator membrane of the battery based on the impedance information and the battery temperature, permit current flow to and from the battery when actual impedance is greater than the threshold impedance, and prevent current flow to and from the battery when the actual impedance is less than or equal to the threshold impedance.

Abstract: A fuel cell stack (100) includes a first supporting substrate (5a), a first power generation element, a second power generation element, a second supporting substrate (5b) and a communicating member (3). The first supporting substrate (5a) includes a first substrate main portion, a first dense layer, and a first gas flow passage. The first dense layer covers the first substrate main portion. The second supporting substrate (5b) includes a second substrate main portion, a second dense layer, and a second gas flow passage. The second dense layer covers the second substrate main portion. The communicating member (3) extends between a distal end portion (502a) of the first supporting substrate (5a) and a distal end portion (502b) of the second supporting substrate (5b) and communicates between the first gas flow passage and the second gas flow passage.

Abstract: Systems, methods, and devices are provided herein for removing a byproduct of a fuel cell from a vehicle. The vehicle comprises a fuel cell and a venting system. The fuel cell is in communication with a fuel storage container. The fuel is configured to generate electricity and a byproduct, by reacting a first fuel from the fuel storage container with a second fuel through an electrochemical reaction. The venting system is configured to expose the byproduct to forced convection.

Abstract: A fuel cell system includes: a fuel cell; a reformer to generate a hydrogen-containing gas; an electric power generation raw material supply unit; a reforming material supply unit configured to supply at least one of reforming water and reforming air, to the reformer; an oxidizing gas supply unit to supply an oxidizing gas to a cathode of the fuel cell; a combustor to ignite an exhaust gas discharged from the fuel cell; and a controller. In an operation stop process of the fuel cell system, the controller causes the oxidizing gas supply unit to supply the oxidizing gas, causes the electric power generation raw material supply unit and the reforming material supply unit to intermittently supply the electric power generation raw material and at least one of the water and the air to the reformer, and causes the ignitor to perform an ignition operation.

Abstract: Methods, systems, and device for controlling air flow within a vehicle for electrical generation. The air control system includes at least one of an air compressor, a back pressure valve or a bypass valve that controls air flow. The air control system includes one or more components. The air control system includes an electronic control unit. The electronic control unit is configured to obtain an air flow target and an air pressure ratio target and determine that the one or more components will operate outside a safe operating region. The electronic control unit is configured to determine a mediated air flow target and a mediated air pressure ratio target that causes the one or more components to operate within the safe operating region. The electronic control unit is configured to adjust the at least one of the air compressor, the back pressure valve or the bypass valve.

Abstract: A method for controlling a fuel cell system includes steps of: (a) determining whether hydrogen (H2) is detected in an interior space of a stack enclosure in which a fuel cell stack is accommodated; (b) stopping power generation that is performed using the stack when it is determined in step (a) that the hydrogen is detected; (c) opening a purge valve to discharge gases circulating in an anode through the purge valve, and opening a condensate discharge valve to discharge condensate contained in a water trap through the condensate discharge valve; and (d) determining whether the hydrogen discharged through at least one of the purge valve and the condensate discharge valve in step (c) flows back to the interior space based on H2 concentration in the interior space.

Abstract: Oilfield electricity and heat generation systems and methods are provided herein. In an embodiment, an oilfield electricity and heat generation system includes a solid oxide fuel cell and a heat exchanger in thermal communication with the solid oxide fuel cell. The fuel cell includes an anode and a cathode that are electrically separated by a solid oxide membrane. The solid oxide fuel cell is adapted to generate electricity and heat from a hydrocarbon fuel source. The heat exchanger is adapted to repurpose thermal energy from the solid oxide fuel cell to heat a reservoir fluid provided from an oilfield well.

Abstract: Disclosed herein are methods and systems that relate to an on-line monitoring of a process/system by controlling rate of oxidation of metal ions at an anode in an anode electrolyte of an electrochemical process and controlling rate of reduction of the metal ions in a catalysis process to achieve steady state.

Abstract: A device for changing an anode inlet and an anode outlet of a fuel cell stack includes an inlet manifold connected the anode inlet of the fuel cell stack and an outlet manifold connected to the anode outlet. An inlet and outlet changing means is disposed inside one of the inlet manifold and the outlet manifold and controls flow directions of the anode inlet and the anode outlet to be the same or opposite to each other.

Abstract: A process for supplying a fuel cell with reactive species, including a stack of electrochemical cells divided into N different groups, wherein a plurality of steps of selectively supplying the N groups of cells with reactive species are carried out, following each of the supply steps, a step of purging the N groups of cells is carried out.

Abstract: A fuel cell system includes a compressor configured to adjust a flow rate of cathode gas to be supplied to a fuel cell and a pressure regulating valve configured to adjust a pressure of the supplied cathode gas. The fuel cell system further includes a controller programmed to calculate a target pressure of the supplied cathode gas while taking into consideration a load of the fuel cell and a heat protecting requirement of the fuel cell system, calculate a target flow rate of the supplied cathode gas in accordance with the load of the fuel cell and the target pressure of the cathode gas, and control the compressor and the pressure regulating valve in accordance with the target pressure and the target flow rate. The controller is further programmed to increase the target flow rate of the cathode gas as the target pressure of the cathode gas becomes lower.

Abstract: In a vehicle including a fuel cell system, an electronic control unit is configured to perform first processing in which a rotation speed of an air pump is controlled based on a torque command value and a rotation speed command value, and to perform, in the first processing, at least one of second processing in which the torque command value is set to be larger than the calculated torque command value when at least one of values of an accelerator position, required electric power, and the rotation speed command value or a change rate thereof is increased by a prescribed first value or more, and third processing in which the torque command value is set to be smaller than the calculated torque command value when at least one of the values or the change rate thereof is decreased by a prescribed second value or more.

Abstract: A power controlling apparatus includes a secondary battery (2) connected to an electrical device (4), and a fuel cell (3) connected to the electrical device (4) and the secondary battery (2). The fuel cell (3) has two non-generating modes including an idling mode and a halt mode, the fuel cell (3) suspending generation of power while being supplied with fuel in the idling mode, the fuel cell (3) stopping generation of power without fuel supply in the halt mode. The power controlling apparatus further includes a remainder estimator (11) to calculate the remaining number of starts representing the remaining number of available starts of the fuel cell (3), and a controller (16) to control the fuel cell (3) to be one of the two non-generating modes during a non-charging mode of the secondary battery (2), based on the remaining number of starts calculated by the remainder estimator (11).

Abstract: A method for operating a fuel cell system includes detecting a pressure in a fuel supply path located downstream of a pressure reducing valve using a pressure sensor. Whether or not the pressure detected by the pressure sensor exceeds a predetermined threshold pressure is determined. The pressure in the fuel supply path located downstream of the pressure reducing is reduced when the pressure detected by the pressure sensor exceeds the predetermined threshold pressure.

Abstract: A method for controlling starting of a fuel cell vehicle is provided. The method includes measuring a time interval for stopping of a fuel cell and a cell average voltage of the fuel cell when the fuel cell vehicle stops. A starting mode is then switched to a catalyst activating mode when the time interval exceeds a predetermined time or the cell average voltage is greater than a predetermined voltage. The cell average voltage is decreased to be less than the predetermined voltage and the fuel cell is started by supplying air to a cathode of the fuel cell.

Abstract: This disclosure relates to energy storage and generation systems, e.g., combination of flow battery and hydrogen fuel cell, that exhibit operational stability in harsh environments, e.g., both charging and discharging reactions in a regenerative fuel cell in the presence of a halogen ion or a mixture of halogen ions. This disclosure also relates to energy storage and generation systems that are capable of conducting both hydrogen evolution reactions (HERs) and hydrogen oxidation reactions (HORs) in the same system. This disclosure further relates to energy storage and generation systems having low cost, fast response time, and acceptable life and performance.

Abstract: The preset invention relates to a solid oxide fuel cell stack capable of producing electricity, in which unit cell modules are connected in series and in parallel, and to a manufacturing method thereof. The solid oxide fuel cell stack is manufactured by: making a unit cell module comprising at least one unit cell formed on the outer surfaces of a flat tubular support, a first electrical interconnector formed on the front end of the support and at least a portion of the outer surfaces so as to be connected to a first electrode of the unit cell, and a second electrical interconnector formed on the rear end of the support and at least a portion of the outer surfaces so as to be connected to a second electrode of the unit cell; and stacking the unit cell modules such that the electrical interconnectors come into contact with each other.

Abstract: A battery module according to the principles of the present disclosure includes a plurality of battery cells, a pair of sideplates, and a pair of endplates. The sideplates are disposed on opposite sides of the plurality of battery cells and the endplates are disposed at opposite ends of the battery module. The sideplates include a first mating portion and the endplates include a second mating portion that engages the first mating portion to provide an interference fit. The interference fit joins the sideplates and the endplates together and bands the plurality of cells together between the sideplates and the endplates.

Abstract: Methods and systems for operation of direct methanol fuel cell (DFMC) systems with enhanced flexibility within a wide range of electrical loads as well as no external load are provided. With these methods and systems, the fuel cell operates at low power in a non shut-down state in a fully controlled manner thus allowing the fuel cell to withstand frost conditions and to maintain optimal ancillary battery capacity.

Abstract: The present invention provides geometric arrangements for channels through which liquids or other fluids can be made to flow, for enhanced performance of fuel cells or other chemical or biochemical reactors or analyzers. Systems and methods including these improved geometries are described herein for enhanced performance of a variety of devices. Specifically, in one set of embodiments, the reactors comprise one or more microchannels comprising a tapered cross-sectional area and at least one reactive surface portion. By flowing a liquid comprising one or more reactants through the channel such that the cross-sectional area decreases in a downstream direction, relatively more reactant may be supplied to the wall at downstream positions relative to the amount that would be supplied in a system without a tapered cross-section. In some embodiments, the microchannel may be constructed and arranged such that the amount of reactant supplied to the wall conforms to a predetermined distribution.

Abstract: A fuel cell includes a direct liquid fuel cell and a humidifier. The direct liquid fuel cell includes an air intake channel for providing oxidant to the fuel cell and an exhaust channel for exhausting depleted oxidant. The humidifier forms a fluid connection between the air intake channel and the exhaust channel.

Abstract: The current invention is a fuel cell controller that includes a first control loop, where the first control loop is disposed to adjust a fuel cell current to regulate a hydrogen output pressure from the fuel cell to a pressure target valve, and further includes a second control loop disposed to adjust a hydrogen flow rate from a hydrogen generator to match a DC/DC power output to a power target value.

Abstract: A fuel cell system includes a cell stack body formed by stacking fuel cells on top of each other, end plates arranged at ends in the cell stacking direction of the cell stack body, and a fluid regulation device mounted in a flow path connected to the cell stack body and regulating conditions of fluid flowing in the flow path. The fluid regulation device is fixed to an end plate only at either of a fluid entrance portion and a fluid exit portion of the fluid regulation device.

Abstract: Flow battery. The battery includes high energy density fluid electrodes having a selected non-Newtonian rheology and structure for providing intermittent flow pulses of controlled volume and duration of the fluid electrodes, the structure adapted to promote interfacial slip to improve flow uniformity. The battery disclosed herein provides a potential solution to large-scale electrical energy storage needs.

Abstract: The object of this invention is to provide a fuel supply system capable of reducing the quantity of a fuel to be discharged from a plurality of fuel tanks connected in parallel is provided. The fuel supply system includes a plurality of the fuel tanks for storing a fuel, on-off valves provided individually for the fuel tanks, and a control unit which controls the opening and closing of the on-off valves. The control unit changes the number of the on-off valves to be simultaneously opened according to a situation. The control unit may reduce the number of the on-off valves to be simultaneously opened after a failure is detected or at the time of maintenance of the fuel supply system.

Abstract: A fuel cell system is disclosed with a fuel cell stack having a plurality of fuel cells, the fuel cell stack including an anode supply manifold and an anode exhaust manifold, a sensor for measuring at least one of an environmental condition affecting the fuel cell stack and a characteristic of the fuel cell stack, wherein the sensor generates a sensor signal representing the measurement of the sensor; and a processor for receiving the sensor signal, analyzing the sensor signal, and controlling a flow rate of a fluid flowing into the anode supply manifold based upon the analysis of the sensor signal.

Abstract: A method a system and method for optimizing the power distribution between a fuel cell stack and a high voltage battery in a fuel cell vehicle. The method includes defining a virtual battery hydrogen power for the battery that is based on a relationship between a battery power request from the battery and an efficiency of the battery and defining a virtual stack hydrogen power for the fuel cell stack that is based on a relationship between a stack power request from the fuel cell stack and an efficiency of the fuel cell stack. The virtual battery hydrogen power and the virtual stack hydrogen power are converted into polynomial equations and added together to provide a combined power polynomial equation. The combined power polynomial equation is solved to determine a minimum of the fuel cell stack power request by setting a derivative of the virtual stack hydrogen power to zero.

Abstract: The present invention relates to a hydrogen fed power system comprising: a high-pressure hydrogen container (150), at least one hydrogen driven energy converter such as a fuel cell (159) connecting to the hydrogen container (150), pressure converter (158) for hydrogen gas, located between the high-pressure hydrogen container (150) and the lower pressure energy converter (159). The invention also relates to a vehicle as well as to a stand-alone electric power unit provided with such an hydrogen fed power system. Furthermore the present invention relates a method for use of the hydrogen fed power system and to a method for filling up the high-pressure hydrogen container of the hydrogen fed power system.

Abstract: A fuel cell is provided with a separator that supports an electrolyte/electrode assembly sandwiched therebetween. The separator is provided with: first and second fuel gas supply parts in the center of which fuel gas supply holes are formed; first and second cross-link parts connected to the first and second fuel gas supply parts; and first and second surrounding support parts connected to the first and second cross-link parts. Each first surrounding support part is provided with a set of fuel gas exhaust passages that discharge fuel gas that has gone through a fuel gas passage and been used. The cross-sectional areas of the fuel gas exhaust passages are larger on the downstream sides than on the upstream sides, in terms of the direction of fuel gas flow.

Abstract: Provided is a fuel cell system including: a wetness detecting section for detecting a wetness of a fuel cell stack; a target SR setting section for setting a target SR of the fuel cell stack based on the wetness; a smallest SR setting section for setting, based on a load, a smallest SR necessary to prevent flooding of the fuel cell stack; and an SR control section for performing control so that an actual SR becomes temporarily larger than the smallest SR when the target SR is smaller than the smallest SR.

Abstract: In a fuel cell system including a fuel cartridge and a fuel supply module, the fuel cartridge includes at least two ports, wherein a first port from among the at least two ports is a fuel inlet port and a second port from among the at least two ports is a fuel outlet port. The fuel cartridge may also include a fuel pouch or the fuel cartridge itself may be the fuel pouch. The fuel supply module may include a fuel circulation structure that circulates the fuel before the fuel is supplied to the stack. The fuel cell system may be equipped with an electronic apparatus and serve as a source of power.

Abstract: A method of and fuel cell system for limiting an amount of a fuel crossing over a membrane in a fuel cell, the method including determining an appropriate molecular ratio of the fuel and water for a fuel-water mixture 503; and controlling an amount of the fuel-water mixture that is available to an anode side of the membrane 507 in the fuel cell according to an amount of the fuel that will be electro-oxidized by the fuel cell. The fuel cell system includes a fuel cell membrane 103 having an anode layer 107, a cathode layer 109, and an electrolyte layer 111 where the cathode layer is exposed to an oxygen source, and a fuel delivery system 105 including a fuel chamber 119 disposed around and proximate to the anode layer at a side opposite to the electrolyte layer, the fuel delivery system implementing the method above.

Abstract: A fuel cell system is provided that includes a fuel cell stack, an air pump, a first convertor, a motor, and an ECU for controlling the air pump and the first convertor based on the target voltage and the switching voltage of the single cell. The ECU executes the first mode such that the actual voltage of the single cell corresponds to the target voltage, when the target voltage is equal to or less than the switching voltage, while the ECU executes the second mode such that the actual voltage of the single cell is kept at the switching voltage, when the target voltage is more than the switching voltage. Further, the ECU executes the second mode thereby to change the actual current of the single cell.

Abstract: A fuel cell system includes an air supply flow path configured to supply the air to a fuel cell, a reed valve provided in the air supply flow path, an air exhaust flow path configured to allow the air discharged from the fuel cell to flow therethrough, a pressure regulating valve provided in the air exhaust flow path and configured to adjust back pressure of the air supplied to the fuel cell, a bypass flow path configured to connect an upstream section of the air supply flow path upstream of the reed valve with the air exhaust flow path, and a bypass valve provided in the bypass flow path and configured to open and close the bypass flow path. The fuel cell system reduces the opening of the pressure regulating valve with supplying the air to the fuel cell in the closed position of the bypass valve, so as to increase the pressure of the air upstream of the pressure regulating valve, and subsequently opens the bypass valve.

Abstract: 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.

Abstract: A method of operating a fuel cell system includes characterizing the fuel or fuels being provided into the fuel cell system, characterizing the oxidizing gas or gases being provided into the fuel cell system, and calculating at least one of the steam:carbon ratio, fuel utilization and oxidizing gas utilization based on the step of characterization.

Abstract: A target value of each of factors in a fuel cell system is determined based on a correspondence relationship of a change in each of the factors determining reaction conditions of fuel in a fuel cell to a change in an external environment of the fuel cell system, and peripheral devices of the fuel cell affecting the reaction conditions of the fuel in the fuel cell are controlled according to a target value of each of the factors.