Abstract: A fuel cell system that recirculates fuel off gas that has not been used for power generation of a fuel cell is provided. The fuel cell system includes a fuel cell stack, a fuel container, a fuel supply path, and a fuel circulation path. The fuel circulation path is connected to a fuel outlet of the fuel cell stack and extends parallel to an end plate of the fuel cell stack. The fuel supply path is connected to the fuel container, extends parallel to the end plate, and merges with the fuel circulation path at a position where a center of the fuel supply path is offset from a center of the fuel circulation path. The fuel circulation path includes a bent portion downstream of a merging portion with the fuel supply path, and is connected to a fuel inlet of the fuel cell stack downstream of the bent portion.

Abstract: An ejector having a nozzle for jetting a hydrogen gas (working fluid), wherein the nozzle includes an inner nozzle and an outer nozzle, both the nozzles are disposed to encompass an axis of a diffuser, an axis of the inner nozzle or an axis of the outer nozzle is arranged to align with the axis, an inner jet hole through which the hydrogen gas flows is formed in the inner nozzle, an outer jet hole having a ring-shaped cross section through which the hydrogen gas flows is provided between the inner nozzle and the outer nozzle, the outer jet hole when a main body casing is horizontally disposed includes an upper hole portion above the axis and a lower hole portion under the axis, and the inner nozzle and the outer nozzle are mutually eccentrically disposed so that the lower hole portion is narrower than the upper hole portion.

Abstract: The fuel cell system is a fuel cell system wherein, when the amount of power generated by a fuel cell is determined to be equal to or less than a predetermined threshold, a controller issues an intermittent supply command to intermittently supply fuel gas to the fuel cell; wherein the intermittent supply command includes a first intermittent supply command and a second intermittent supply command; wherein the first intermittent supply command increases the flow rate of the fuel gas by setting the opening degree during pressure rise of a linear solenoid valve to relatively more than the second intermittent supply command; and wherein, after the first intermittent supply command, the second intermittent supply command decreases the flow rate of the fuel gas for a predetermined time by setting the opening degree during pressure rise of the linear solenoid valve to relatively less than the first intermittent supply command.

Abstract: To provide a fuel cell system configured to, at the time of starting the fuel cell system, purge gas other than fuel gas from the fuel electrodes of a fuel cell stack in a short time. A fuel cell system comprising: a fuel cell stack, an ejector set, a fuel gas supplier, a circulation flow path, a mixed gas supply flow path, a pressure detector which detects pressure information of a fuel electrode side of the fuel cell stack, a fuel off-gas discharger which discharges the fuel off-gas, in which a concentration of the fuel gas is a predetermined concentration or less, to the outside, and a controller, wherein the ejector set includes a first ejector and a second ejector in parallel, the first ejector being an ejector which supplies first mixed gas to the fuel electrodes of the fuel cell stack, and the second ejector being an ejector which supplies second mixed gas, in which a content ratio of the circulation gas is larger than the first mixed gas, to the fuel electrodes of the fuel cell stack.

Abstract: In a plan view of the fuel cell unit viewed from an auxiliary device side, an area surrounded by an outer edge of a first auxiliary device is referred to as an area A, an area surrounded by an outer edge of a fuel cell stack is referred to as an area B 1, an area surrounded by an outer edge of a power converter is referred to as an area B2, and an area obtained by adding the area B1 and the area B2 together is referred to as an area B3. The area A overlaps at least part of the area B1 and at least part of the area B2. An entirety of the area A is included inside the area B3.

Abstract: A fuel cell system includes a fuel cell, a fuel gas supply device, an oxidant gas supply device, a refrigerant supply device, a fuel cell temperature measurement device configured to measure a temperature of the fuel cell, and a control unit. The control unit is configured to, when the temperature of the fuel cell is lower than a target temperature, perform a warm-up operation to increase the temperature of the fuel cell to the target temperature by generating the electric power with the fuel cell while cooling the fuel cell with the oxidant gas by stopping supply of the refrigerant and controlling an amount of the oxidant gas supplied.

Abstract: To provide a fuel cell system configured to suppress irreversible performance degradation of a fuel cell. A fuel cell system wherein the controller preliminarily stores a data group indicating a relationship between, when a predetermined amount of hydrogen gas is supplied from the fuel gas supplier, an amount of the supplied hydrogen gas and a hydrogen pressure increase rate; wherein the controller calculates a fuel gas pressure increase rate from a pressure change detected by the pressure sensor when the fuel gas is supplied to the fuel cell; wherein the controller determines whether or not the fuel gas pressure increase rate is smaller than the hydrogen pressure increase rate; and wherein, when the controller determines that the fuel gas pressure increase rate is smaller than the hydrogen pressure increase rate, the controller prohibits power generation of the fuel cell.

Abstract: To provide a fuel cell system configured to reduce false cross leak judgment. A fuel cell system wherein the controller preliminarily stores a first data group indicating a relationship between the flow rate of the oxidant gas, the opening degree of the bypass valve, and the hydrogen concentration of the oxidant off-gas; and wherein before the controller determines whether or not a cross leak has occurred, the controller varies the hydrogen concentration threshold used for determining whether or not a cross leak has occurred, by comparing the flow rate of the oxidant gas measured by the oxidant gas flow rate sensor and the opening degree of the bypass valve with the first data group.

Abstract: A fuel cell system includes a fuel cell that generates electricity by causing reaction of a fuel component contained in fuel gas, a supply path, a control valve, an ejector, a return path, and a controller. The control valve is provided on the supply path. The ejector is provided in a section on the supply path between the control valve and the fuel cell. The return path is connected between an exhaust port of the fuel cell and the ejector, and returns off-gas discharged from the exhaust port to the supply path by suction force generated by the ejector. The controller selectively executes a normal operation and a particular operation. In the particular operation, the control valve is continuously or intermittently opened to a second opening degree smaller than a first opening degree, when the fuel gas is supplied to the fuel cell at a first supply amount.

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: A fuel cell system includes: a fuel cell that includes an installation port and a discharge port for a reactant gas; a first injection device that intermittently injects the reactant gas; second and third injection devices that continuously inject the reactant gas; an ejector that includes an ejection port for the reactant gas from the first or second injection device and the discharge port; a first flow passage that connects the installation port and the ejection port; a second flow passage through which the reactant gas from the third injection device is led to the first flow passage without the ejector; and a control device that performs a warm-up operation by executing the injection of the third injection device, executes the injection of the second injection device, and executes the injection of the first injection device after completion of the warm-up operation.

Abstract: A fuel cell system wherein, at the time of activating the fuel cell system, the controller determines whether or not the temperature of the fuel cell detected by the temperature sensor is equal to or less than a temperature corresponding to activation at sub-zero temperatures, and wherein, when the controller determines that the temperature of the fuel cell detected by the temperature sensor is equal to or less than the temperature corresponding to the activation at sub-zero temperatures, the controller sends a command to the fuel gas supplier to supply the fuel gas to the fuel cell, and the controller controls rotation of the circulation pump to stop a flow of the fuel off-gas in the circulation flow path.

Abstract: A fuel cell system that can offer fuel efficiency and water drainage performance which are compatible with each other, the fuel cell system including a fuel cell stack; a fuel gas supply device; a gas-liquid separator; a pressure measuring device; and a controlling unit, wherein the controlling unit controls pulsed operation of the fuel gas supply device in such a way that a measured pressure is within the range of a preset upper limit pressure and lower limit pressure, and the controlling unit uses a flow rate increasing control at least once when the pressure rises in the pulsed operation before the pressure reaches the upper limit pressure, as long as the pressure does not exceed the upper limit pressure, the flow rate increasing control being to increase the supply of the fuel gas supplied by means of the fuel gas supply device.

Abstract: A fuel cell system includes a fuel cell stack in which a plurality of unit cells is stacked, a detection unit configured to detect a cell voltage of at least one of the unit cells, a converter configured to regulate an output current of the fuel cell stack, and a control device configured to control the converter. The control device executes current reduction processing for reducing the output current in a stepwise manner when the cell voltage detected by the detection unit is a negative voltage.

Abstract: A fuel cell system includes a fuel cell stack in which a plurality of unit cells is stacked, a detection unit configured to detect a cell voltage of at least one of the unit cells, a converter configured to regulate an output current of the fuel cell stack, and a control device configured to control the converter. The control device executes current reduction processing for reducing the output current in a stepwise manner when the cell voltage detected by the detection unit is a negative voltage.

Abstract: A fuel cell system includes a fuel cell generating electric power by a reaction between a fuel gas and an oxidant gas, an injector supplying the fuel gas to the fuel cell, a discharge line in which an off-gas discharged from the fuel cell flows, an ejector recirculating the off-gas flowing in the discharge line to the fuel cell using a flow of the fuel gas from the injector, a discharge valve discharging the off-gas flowing in the discharge line to the outside, and a control device controlling supply of the fuel gas by the injector and opening and closing of the discharge valve. When supply of the fuel gas by the injector is stopped, the control device opens the discharge valve while the off-gas is recirculated to the fuel cell and closes the discharge valve before supply of the fuel gas by the injector is restarted.

Abstract: To suppress the generation of condensed water and suppress the flow of the condensed water into a fuel cell stack. A fuel cell system comprising: a fuel cell stack, an elector set, a fuel gas supplier which supplies fuel gas to the ejector set, a circulation flow path, a mixed gas supply flow path, a temperature detector which detects a temperature of the fuel gas, and a controller, wherein the ejector set includes at least two ejectors in parallel, which are a first ejector that supplies first mixed gas to the fuel electrodes of the fuel cell stack, and a second ejector that supplies second mixed gas, in which a content ratio of the circulation gas is smaller than the first mixed gas, to the fuel electrodes of the fuel cell stack.

Abstract: To provide a fuel cell system configured to reduce the drying of the inside of the fuel cell stack and increase the power generation performance of the fuel cell stack by reducing a circulation gas flow rate during high temperature operation. Disclosed is a fuel cell system comprising: a fuel cell stack, an ejector, a first injector which supplies fuel gas to the ejector, a second injector which has a smaller fuel gas injection amount than the first injector and which supplies the fuel gas to the ejector, a third injector which supplies the fuel gas to fuel electrodes of the fuel cell stack, a fuel gas supplier, a first supply flow path, a second supply flow path which enables the supply of the fuel gas from the third injector to the fuel electrodes of the fuel cell stack, a circulation flow path, a temperature detector, and a controller.

Abstract: A fuel cell system that can offer fuel efficiency and water drainage performance which are compatible with each other, the fuel cell system including a fuel cell stack; a fuel gas supply device; a gas-liquid separator; a pressure measuring device; and a controlling unit, wherein the controlling unit controls pulsed operation of the fuel gas supply device in such a way that a measured pressure is within the range of a preset upper limit pressure and lower limit pressure, and the controlling unit uses a flow rate increasing control at least once when the pressure rises in the pulsed operation before the pressure reaches the upper limit pressure, as long as the pressure does not exceed the upper limit pressure, the flow rate increasing control being to increase the supply of the fuel gas supplied by means of the fuel gas supply device.

Abstract: To provide a fuel cell system configured to reduce false cross leak judgment. A fuel cell system wherein the controller preliminarily stores a first data group indicating a relationship between the flow rate of the oxidant gas, the opening degree of the bypass valve, and the hydrogen concentration of the oxidant off-gas; and wherein before the controller determines whether or not a cross leak has occurred, the controller varies the hydrogen concentration threshold used for determining whether or not a cross leak has occurred, by comparing the flow rate of the oxidant gas measured by the oxidant gas flow rate sensor and the opening degree of the bypass valve with the first data group.