Disclosed are a deterioration estimation system for the fuel cell, a hydrogen supply system for a fuel cell including the same, and a hydrogen supply method for a fuel cell, the deterioration estimation system including a fuel cell which receives hydrogen gas and oxidizing gas respectively supplied to an anode side and a cathode side thereof to generate electrical power, a hydrogen supply line which is connected to the anode side of the fuel cell and supplies gas containing hydrogen gas to the fuel cell, a hydrogen supply valve which is located between the hydrogen supply line and a hydrogen tank, supplies, when opened, hydrogen gas stored in the hydrogen tank to the hydrogen supply line, and blocks the supply of the hydrogen gas when closed, and a deterioration estimating unit which estimates the deterioration state of the fuel cell, based on the opening and closing control of the hydrogen supply valve or a change in the pressure in the hydrogen supply line.

A fuel cell deterioration prevention system includes a cell voltage stability determination unit determining cell voltage stability according to a preset operating condition, a fuel cell deterioration diagnosing unit diagnosing deterioration of a fuel cell by changing and controlling a control variable pre-selected according to an operating condition and monitoring a resultant change in the cell voltage of the fuel cell, and a deterioration avoidance operation control unit performing a deterioration avoidance operation based on a diagnosis result of the fuel cell deterioration diagnosing unit.

In an electrolyte sheet for a solid oxide fuel cell according to the present invention, the number of flaws on at least one of surfaces of the sheet detected by a fluorescent penetrant inspection is 30 points or less in each of sections obtained by dividing the sheet into the sections each measuring 30 mm or less on a side. A unit cell for a solid oxide fuel cell according to the present invention comprises a fuel electrode, an air electrode, and the electrolyte sheet for a solid oxide fuel cell according to the present invention, which is disposed between the fuel electrode and the air electrode. A solid oxide fuel cell of the present invention includes the unit cell for a solid oxide fuel cell according to the present invention.

A fuel cell system comprises a controller configured to determine whether a condition relating to a stop pattern of the fuel cell system satisfies a predetermined condition, and an output unit configured to output a warning when it is determined that the condition relating to the stop pattern satisfies the predetermined condition.

a fuel cell system without a high pressure line of a hydrogen supplying system, including a gas charging line formed between a gas charging station and a high pressure vessel charged with gas by the gas charging station, and a gas supplying line formed between the high pressure vessel and a stack, includes: a regulator provided in the gas supplying line; a solenoid valve provided in the gas supplying line between the regulator and the high pressure vessel; and a check valve provided in a bypass line connecting one point of the gas supplying line between the regulator and the solenoid valve and one point of the gas charging line.

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.

The fuel cell system includes: a fuel cell; an anode supply pipe; a fuel gas supplier disposed at the anode supply pipe, the fuel gas supplier configured to adjust a supply quantity of a fuel gas to be supplied to the fuel cell; an ejector disposed at the anode supply pipe at a position between the fuel gas supplier and the anode supply port; an anode circulation pipe connected to the anode discharge port and the ejector; a circulation stop unit disposed at the anode circulation pipe, the circulation stop unit configured to stop circulation of the fuel gas through the anode circulation pipe; a pressure sensor configured to detect a pressure in the anode supply pipe at a position between the ejector and the anode supply port; and a controller. When a first pressure acquired from the pressure sensor is equal to or less than a predetermined lower limit value, the controller controls the fuel gas supplier to perform constant quantity supply control to supply the fuel gas of a predetermined supply quantity, and controls the circulation stop unit to perform circulation stop control to stop the circulation through the anode circulation pipe, and the controller determines abnormality at the ejector and the anode circulation pipe by using a second pressure acquired from the pressure sensor after the fuel gas supplier performs the constant quantity supply control and the circulation stop unit performs the circulation stop control.

A fuel cell system includes: a fuel cell; a first valve device provided at an oxidation gas supply channel; a second valve device provided at an oxidation off-gas discharge channel; a third valve device provided at a bypass channel; an abnormality detection unit configured to detect an abnormality; and a control unit. The control unit causes the fuel cell to initiate fail-safe power generation if (i) a different abnormality from a valve opening abnormality is detected in the first valve device, (ii) the different abnormality is detected in the second valve device, or (iii) any abnormality is detected in the third valve device. During the fail-safe power generation, if any abnormality is additionally detected in any valve device different from the valve device in which an abnormality is already detected, the control unit stops power generation by the fuel cell.

A control method for a fuel cell system includes: acquiring a poisoning rate of an electrode catalyst of a fuel cell; performing a potential maintaining operation of maintaining a potential of the fuel cell in a first potential range when the poisoning rate of the electrode catalyst is greater than a prescribed value α; and performing a potential changing operation of repeating a cycle in which the potential of the fuel cell is changed between an upper-limit potential and a lower-limit potential of a second potential range which is higher than the first potential range after the potential maintaining operation has been performed.

A method of inspecting short circuit of an electrolyte membrane by a short circuit inspection apparatus includes an obtaining step of performing a process of obtaining the energization state of a limited range including divided portions that are adjacent to each other in a range which is smaller than the entire range of the plurality of divided portions, for each of a plurality of limited ranges provided at different positions, and a determination step of determining whether or not a short circuit portion is present in the electrolyte membrane based on the energization state of the plurality of limited ranges.