Abstract: A fuel cell system of the present invention is mounted on a moving object and is equipped with a fuel cell for generating power by chemically reacting a fuel gas supplied to an anode and an oxidizer gas supplied to a cathode; a cooling mechanism for cooling the fuel cell by radiating heat of a refrigerant circulating in the fuel cell into an atmosphere; a speed detection mechanism for detecting a moving speed of the moving object; an outside air temperature detection mechanism for detecting an outside air temperature; a cooling amount estimation mechanism for estimating a cooling amount of the fuel cell by the cooling mechanism, based on the moving speed and the outside air temperature; and an upper limit value set mechanism for setting an upper limit value of a power generation current, based on an estimation result of the cooling amount estimation mechanism.

Abstract: In a fuel cell system including a fuel cell supplied with reaction gases for generating an electric power, and a combustion heater supplied with the reaction gases for heating the fuel cell during warming-up, an electric discharging circuit is provided to discharge an electric current from the fuel cell supplied with the reaction gases to decrease a voltage difference applied to the membrane sandwiched between the anode and cathode during the warming-up. The combustion heater is connected in series or in parallel with the fuel cell system.

Abstract: A fuel cell system allows suppression of the deterioration of a fuel cell even if a part of a membrane configuring the fuel cell is unavailable for power production. The fuel cell is configured with a membrane, and an anode and a cathode provided so as to sandwich the membrane, and produces electric power from reaction of reactive gases via the membrane when the reactive gases are supplied to the anode and the cathode. The fuel cell system is configured with the fuel cell, an MEA power production effective area calculating means for calculating an area of the membrane surface available for power production, an upper limit power producing current calculating means for controlling the total power production of the fuel cell based on the power production effective area calculated by the MEA power production effective area calculating means, and a current controller.

Abstract: A scavenging process is performed on the anode side by opening an air supply valve to remove liquid droplets in a fuel gas flow field using the compressed air from an air compressor. During the scavenging process, when a start up signal from an ignition switch is received, the start up of a fuel cell is prohibited until the gas in the fuel gas flow field is replaced completely by air.

Abstract: After an ignition switch is turned off, in order to suppress operation of an air compressor and thereby reduce noise, liquid droplets residing in an oxygen-containing gas flow field as well as liquid droplets residing in a fuel gas flow field are removed during separate time periods, such that the flow rate in the oxygen-containing gas flow field and the flow rate in the fuel gas flow field do not become large at the same time. Then, an electrolyte membrane is dried using an oxygen-containing gas, in order to improve the performance upon starting a next operation.

Abstract: A fuel cell system includes a fuel cell, an operation controller, a checking unit, a scavenging unit, an instructing unit, a temperature sensor, a humidifier and a humidification controller. The operation controller selects one of a normal operation mode and a low-temperature operation mode. The checking unit determines whether the fuel cell has been started up in the low-temperature operation mode. The instructing unit provides an instruction for a shutoff of electricity generation. When the scavenging unit conducts scavenging based on the checking unit determining that the fuel cell has been started in the low-temperature operation mode in response to an instruction for a shutoff of electricity generation and an actual temperature of the fuel cell is higher than a predetermined temperature, the humidification controller controls an amount of humidification according to the actual temperature.

Abstract: This fuel cell system is equipped with a fuel cell having a reaction gas flow passage, generating power by the reaction gas being supplied to the reaction gas flow passage, having a refrigerant flow passage, and cooled by the refrigerant being supplied to the refrigerant flow passage; a reaction gas supply device for supplying the reaction gas to the reaction gas flow passage; a refrigerant supply device for supplying the refrigerant to the refrigerant flow passage; a refrigerant supply restriction device for restricting a refrigerant supply amount to the refrigerant flow passage; and a controller for controlling the refrigerant supply restriction device, wherein the reaction gas refrigerant supply devices have a drive device in common and are integrally driven, and wherein when warming up the fuel cell, the controller controls the refrigerant supply restriction device and reduces the refrigerant supply amount to the refrigerant flow passage.

Abstract: A fuel-cell system 1 includes: a fuel cell 13 configured to generate electricity through reaction between hydrogen gas and air; a compressor 12 configured to supply air as a scavenging gas to a reactant gas path 13a of the fuel cell 13; a control part 18 configured to control an amount of air supplied from the compressor 12 to the fuel cell 13 to perform scavenging of the fuel cell 13; and pressure sensors P1 and P2 configured to monitor a pressure drop in the reactant gas path 13a of the fuel cell 13. The control part 18 controls an amount of supplied air so as to keep the pressure drop in the reactant gas path 13a substantially constant when the fuel cell 13 is scavenged. With this configuration, residual water can be suitably purged from the fuel cell while energy consumption is suppressed.

Abstract: A fuel cell system is provided which estimates a water content in a fuel cell based on a predetermined map using an integrated value of electric current generated by the fuel cell (ST4) before power generation is stopped (ST5). When a temperature of the fuel cell has fallen lower than a predetermined value (ST7) after the power generation is stopped (ST5), the fuel cell system determines a dry degree in the fuel cell (ST8) and an anode scavenging period (ST9) based on predetermined maps. Scavenging is performed in an anode in the fuel cell for the anode scavenging period (ST10).

Abstract: A fuel cell system and a method for scavenging it are provided. The fuel cell system includes a fuel cell, a fuel gas passage, an oxidant gas passage, a communicating passage, a communicating valve, a monitoring device, a valve controller, a scavenging device and a computing device. The monitoring device monitors a state transition of the fuel cell after a termination of power generation. The valve controller opens the communicating valve when a signal indicative of the state transition meets a predetermined criterion. The scavenging device includes a first scavenging device for the oxidant gas passage, and a second scavenging device for the fuel gas passage. The computing device computes an amount of the oxidant gas required for scavenging according to a system shut off time. The scavenging device conducts scavenging with the amount of the oxidant gas obtained by the computing device.

Abstract: When it is detected that the ignition switch is turned off a short period of time after the ignition switch turned on at the temperature below the freezing point, the charge threshold of a capacitor is changed to a larger charge threshold C for increasing the amount of electrical energy charged in the capacitor based on the charge threshold C. The capacitor is used for performing a scavenging process for a sufficient period of time. At the time of starting operation of the fuel cell system at the temperature below the freezing point the next time, using the electrical energy of the capacitor, a fuel cell is warmed rapidly by a heater or the like to start operation of the fuel cell system.

Abstract: There is provided a fuel cell for generating a electric power by a reaction of a reaction gas, a reaction gas flow path through which the reaction gas passes, purge section for purging the reaction gas flow path with a purging gas, a purge judging section for judging as to whether or not a purging operation by the purge section is required, and a failure detecting section for detecting a failure of a judgment support device. When the failure of the judgment support device is detected by the failure detecting section, there action gas flow path is purged by the purge section when stopping the power generation of the fuel cell.

Abstract: A fuel cell system wherein even if the fuel cell is exposed to a cold environment, stabilization of power generation is possible. The fuel cell system comprises: a fuel cell in which electric power is generated by a reaction of reaction gases; purging means for purging at least one of reaction gas flow paths through which reaction gases flow; thermal detecting means for detecting a temperature of the fuel cell; low-temperature determining means, which determines that the temperature of the fuel cell is low every time it is below a predetermined temperature; and purging control means for purging the fuel cell when the low-temperature determining means determines, after an input of a power generation stop signal, that the temperature of the fuel cell is low.

Abstract: A reaction gas is supplied to a cathode side of a fuel cell at a flow rate higher than that for a usual operation of the fuel cell to thaw the fuel cell system at startup in a freezing state of the system when the system has experienced a temperature lower than an operation temperature of an anode off-gas. A thawing state of the system is detected on the basis of at least two of temperatures of the anode off-gas, a cathode off gas, and a radiator liquid of the fuel cell to control supplying the reaction gas to the cathode side at a usual operation flow rate. An actual increase rate of the temperature of the anode off-gas is obtained and an increase rate of the temperature of the anode off-gas is calculated from the self-heating value to be compared to determine the thawing state.

Abstract: A fuel cell system includes a fuel cell having a fuel gas flow path and an oxidant gas flow path; a compressor for supplying humidified air to the oxidant gas flow path; a back-pressure regulating valve for controlling pressure of humidified air in the oxidant gas flow path; a pressure sensor for measuring the pressure of the humidified air in the oxidant gas flow path; and a control section for controlling the compressor and the back-pressure regulating valve. In this system, the pressure of humidified air in the oxidant gas flow path is regulated to become equal or approximate to a target pressure by the back-pressure regulating valve. When the pressure difference between the pressure measured by the pressure sensor and the target pressure is larger than a predetermined pressure difference, the control section corrects operating conditions of the compressor, so that the measured pressure becomes the target pressure.

Abstract: A fuel cell system enables time required for purging to be reduced without a major increase in discharge gas concentration at a time of purging. It comprises a fuel cell; a fuel gas supply path for supplying the fuel gas to an anode; an oxidizing gas supply path for supplying an oxidizing gas to a cathode; a fuel gas circulating path for returning an unreacted fuel gas to an anode inlet side; a dilution box for diluting the fuel gas by the oxidizing gas and for discharging it to outside; and a fuel gas discharge path connecting the fuel gas circulating path and a dilution box discharge gas inlet. A drain valve, a purge valve and an air discharge valve are provided, opening areas of which are different from one another. The drain valve with a smallest opening area is initially opened.

Abstract: The following control is performed. During startup of a fuel cell 1, a fuel gas is supplied to an anode 1b of the fuel cell 1 and an oxidant gas is supplied to a cathode 1c of the fuel cell 1, thereby starting power generation. Fuel gas externally emitted from the abode 1b is diluted with an oxidant gas externally emitted from the cathode 1c. From a start to end of discharge of a fuel gas from the anode 1b, a flow rate required for dilution of the oxidant gas, and a flow rate required for an external output, being calculated on the basis of the power requested for the fuel cell 1, are respectively calculated. The flow rate required for dilution and the flow rate required for an external output are compared, and a larger flow rate is set as a flow rate of the oxidant gas.

Abstract: A fuel cell system of the present invention is mounted on a moving object and is equipped with a fuel cell for generating power by chemically reacting a fuel gas supplied to an anode and an oxidizer gas supplied to a cathode; a cooling mechanism for cooling the fuel cell by radiating heat of a refrigerant circulating in the fuel cell into an atmosphere; a speed detection mechanism for detecting a moving speed of the moving object; an outside air temperature detection mechanism for detecting an outside air temperature; a cooling amount estimation mechanism for estimating a cooling amount of the fuel cell by the cooling mechanism, based on the moving speed and the outside air temperature; and an upper limit value set mechanism for setting an upper limit value of a power generation current, based on an estimation result of the cooling amount estimation mechanism.