Abstract: A fuel cell system includes: a fuel cell; a fuel gas path supplied with fuel and allowing a part of fuel gas discharged from the fuel cell to circulate; an exhaust mechanism discharging the reacted fuel gas to an outside; a circulation mechanism circulating the fuel gas; and a control unit configured to temporarily stop circulation of the fuel gas by the circulation mechanism when determining that discharge from the exhaust mechanism is not normal, drive the circulation mechanism so that the fuel gas circulates at a first circulation speed when determining that the discharge is not normal and a parameter relating to water vapor in the fuel gas path is equal to a predetermined value or greater, and drive the circulation mechanism so that the fuel gas circulates at a second circulation speed greater than the first circulation speed when determining that the discharge is normal.

Abstract: There is provided a fuel cell system, wherein a controller configured to set the flow volume of a fluid in an anode flow path at an outlet of an anode of the fuel cell to a first flow volume, then set thereafter the flow volume of the fluid in the anode flow path at the outlet of the anode to a second flow volume which is smaller than the first flow volume, and discharge the water in the hydrogen discharge flow path by opening an exhaust and drain valve while the fluid is flowing at the second flow volume.

Abstract: To provide a technique that allows prompt detection of leakage of fuel gas in a fuel cell system. A controller included in a fuel cell system performs a hydrogen leakage detecting process of detecting the occurrence of hydrogen leakage in the low-pressure zone based on the detected pressure in a low-pressure zone of an anode gas piping at a time of start-up of the fuel cell system. A controller uses at least one of a first condition and a second condition for determination as a determination condition in hydrogen leakage detecting process, and determines that there is no leakage of the reactive gas while the fuel cell stops generating power if the determination condition is satisfied.

Abstract: A fuel cell system 10 includes a fuel cell 20, gas supply systems 30, 40, which supply gases to the fuel cell 20, and a controller 60, which controls the gas supply systems 30, 40. During a non-operation period of the fuel cell 20, the controller 60 controls the gas supply systems 30, 40 to carry out the scavenging treatment. If the scavenging treatment is interrupted by an operation performed by a user, then the controller 60 controls the gas supply systems 30, 40 and restarts the scavenging treatment after a predetermined time elapses from the interruption.

Abstract: To provide technology that is capable of inhibiting a decrease in starting properties of a pump in a low-temperature environment. A fuel cell system is equipped with a control unit, a fuel cell, and a pump. The control unit acquires the temperature of the fuel cell as a parameter expressing the temperature of the pump while operation of the fuel cell is stopped. The control unit rotates rotation body of the pump when it is detected that the temperature of the pump is a threshold value or less set within a predetermined range lower than the freezing point based on the detected temperature of the fuel cell.

Abstract: The method comprises: determining whether or not an inlet temperature is equal to or above a lower-limit temperature of a temperature range in which generated water does not freeze within the fuel cell; and adjusting the flow rate of the cooling medium in the circulation flow path to become more than the normal flow rate when it is determined that the inlet temperature is equal to or above the lower-limit temperature, and adjusting the flow rate of the cooling medium in the circulation flow path to be equal to or below the normal flow rate when it is determined that the inlet temperature is not equal to or above the lower-limit temperature.

Abstract: A method includes predicting, while fuel cell system is operated, whether or not the outside temperature becomes equal to or less than a first predetermined temperature; performing, when it is predicted that the outside temperature becomes equal to or less than the first predetermined temperature, residual water scavenging processing on only an oxidizer gas supply/discharge mechanism and thereafter stopping the operation of the fuel cell system; predicting, after the stop of the operation of the fuel cell system, whether or not the temperature of a predetermined component included in the fuel cell system becomes equal to or less than a second predetermined temperature; and performing the residual water scavenging processing on the fuel gas supply/discharge mechanism when it is predicted that the temperature of the predetermined component becomes equal to or less than the second predetermined temperature.

Abstract: A fuel cell system includes: a power supply circuit including a fuel cell and a secondary battery; an oxidant gas supply flow passage; a pump; and a control unit configured to drive the pump and dilute hydrogen retained in an cathode. The control unit is configured to stop supplying an oxidant gas to the cathode by stopping an operation of the pump such that dilution of the hydrogen retained in the cathode is stopped, while the fuel cell vehicle remains stationary after a starter switch of the fuel cell vehicle is switched from an off state to an on state, or while a load required of the power supply circuit remains smaller than a predetermined value after the starter switch of the fuel cell vehicle is switched from the off state to the on state.

Abstract: The operation control method of a fuel cell includes acquiring a startup temperature of the fuel cell; acquiring a present temperature of the fuel cell; setting a present target operation point of the fuel cell that is identified by an output voltage value and an output current value based on the startup temperature, or based on the startup temperature and the present temperature; controlling at least one of the flow of the reaction gas supplied to the fuel cell, and an output voltage of the fuel cell so that the operation point of the fuel cell becomes the target operation point, and setting the target operation point includes a process of setting an operation point having a low output voltage value as the target operation point when the startup temperature is low as compared to the case when the startup temperature is high, if the present temperature is the same.

Abstract: A fuel cell system comprises a fuel cell stack, a circulation flow path of a cooling medium, a pump provided in the circulation flow path, a supply-side temperature sensor provided to detect a supplied cooling medium temperature, a discharge-side temperature sensor provided to detect a discharged cooling medium temperature, and a cold-start controller configured to control a circulation volume of the cooling medium by the pump at a cold start of the fuel cell stack. The cold-start controller estimates a fuel cell internal temperature and selectively sets the circulation volume of the cooling medium between a reduced volume and a normal volume, based on a magnitude relationship between the internal temperature and the discharged cooling medium temperature.

Abstract: If a required voltage which corresponds to a required power has reached a boundary voltage, which is an oxidation-reduction potential of platinum, which constitutes a catalyst of a fuel cell, the fuel cell system performs crossover-avoidance control that holds an FC instruction voltage for the fuel cell at the boundary voltage, and absorbs the gap between the required voltage and the FC instruction voltage by using a secondary battery.

Abstract: A fuel cell system includes: a fuel cell including a cell laminate; an estimating unit for estimating a residual water content distribution in the reactant gas flow channel in a cell plane of each of the single cells and a moisture content distribution in the electrolyte membrane in consideration of water transfer through the electrolyte membrane between the anode electrode and the cathode electrode; and an operation control unit for limiting an electric current drawn from the fuel cell when a residual water content in the reactant gas flow channel estimated by the estimating unit is equal to or above a predetermined threshold.

Abstract: A fuel cell system comprises: a fuel cell formed of a plurality of cells stacked therein, each cell generating electric power through an electrochemical reaction between a fuel gas and an oxidant gas; a cell monitor capable of detecting a group voltage for each group wherein each group is composed of two or more cells; and an estimation device that estimates a minimum cell voltage. The estimation device comprises a maximum cell voltage estimation part that estimates a maximum cell voltage, and the estimation device estimates the minimum cell voltage by using an estimated value of the maximum cell voltage and a minimum group-average voltage, where an average voltage of a group having the lowest voltage value among the group voltages is defined as the minimum group-average voltage.

Abstract: A fuel cell system comprises: noise detection means for detecting the magnitude of noise in a driver's cabin of a fuel cell vehicle in which the fuel cell system is installed; and a control apparatus for controlling the operation of auxiliary machines. The control apparatus performs high-potential avoidance control to increase electric power consumed by the auxiliary machines so that a power-generation voltage of a fuel cell 1 becomes equal to or lower than a predetermined value, based on noise detected by the noise detection means.

Abstract: It is an object of the invention to improve the accuracy of estimating a moisture content and suppress an effect of remaining water at the startup of the fuel cell system. A fuel cell system includes: a fuel cell including a cell laminate; an estimating unit for estimating a residual water content distribution in the reactant gas flow channel and a moisture content distribution in the electrolyte membrane in a cell plane of each single cell while taking into consideration water transfer that occurs between the anode electrode and the cathode electrode via the electrolyte membrane; and an operation control unit for, based on an estimation result from the estimating unit, setting a scavenging time used in a scavenging process for the fuel cell after the fuel cell system is shut down.

Abstract: The water content estimation apparatus for a fuel cell includes an estimating unit for estimating a residual water content distribution in a reactant gas flow channel and a moisture content distribution in an electrolyte membrane in a cell plane of a single cell while taking into consideration water transfer that occurs between an anode electrode and a cathode electrode via the electrolyte membrane between the anode electrode and the cathode electrode. The fuel cell system performs control based on an estimation result by the estimating unit so that the fuel cell assumes a predetermined water condition.

Abstract: The aim of the invention is to improve the accuracy of estimating residual water content in a fuel cell system adopting an intermittent operation mode and to accurately suppress cell voltage reduction due to water accumulation caused by the intermittent operation. The fuel cell system includes: a fuel cell having a cell laminate; an estimating unit for estimating a residual water content distribution in a reactant gas flow channel and a moisture content distribution in an electrolyte membrane in a cell plane of each single cell while taking into consideration water transfer that occurs between an anode electrode and a cathode electrode via the electrolyte membrane; and an operation control unit which changes the content of an intermittent operation when a residual water content in the reactant gas flow channel estimated by the estimating unit is equal to or greater than a predetermined threshold.

Abstract: An object of the invention is to provide a fuel cell system capable of improving accuracy of water content estimation during a standstill. A fuel cell system includes a fuel cell having a plurality of single cells laminated together and an estimating unit for estimating residual water content distributions in a fuel gas flow channel and an oxidation gas flow channel and a moisture content distribution in an electrolyte membrane in a cell plane of each single cell while taking into consideration water transfer that occurs between an anode electrode and a cathode electrode via the electrolyte membrane. The estimating unit estimates a residual water content of the fuel gas flow channel during a standstill from a shutdown to a restart of the fuel cell system based on temperature information on each single cell acquired during the standstill.

Abstract: A fuel cell system includes: a fuel cell including a cell laminate; an estimating unit for estimating a residual water content distribution in the reactant gas flow channel in a cell plane of each of the single cells and a moisture content distribution in the electrolyte membrane in consideration of water transfer through the electrolyte membrane between the anode electrode and the cathode electrode; and an operation control unit for limiting an electric current drawn from the fuel cell when a residual water content in the reactant gas flow channel estimated by the estimating unit is equal to or above a predetermined threshold.

Abstract: The water content estimation apparatus for a fuel cell includes an estimating unit for estimating a residual water content distribution in a reactant gas flow channel and a moisture content distribution in an electrolyte membrane in a cell plane of a single cell while taking into consideration water transfer that occurs between an anode electrode and a cathode electrode via the electrolyte membrane between the anode electrode and the cathode electrode. The fuel cell system performs control based on an estimation result by the estimating unit so that the fuel cell assumes a predetermined water condition.