A fuel cell system includes: a supply flow path configured to supply reactant gas; a first branch flow path branching off from an outlet end of the supply flow path and configured to guide the reactant gas to a first fuel cell stack; a second branch flow path branching off from the outlet end of the supply flow path and configured to communicate with the first branch flow path and guide the reactant gas to a second fuel cell stack; and an inlet area change part disposed in a boundary zone between the first branch flow path and the second branch flow path and configured to selectively change inlet areas of the first and second branch flow paths. Efficiency in discharging condensate water is increased and performance and operational efficiency are improved.

A fuel supply control system and method for a fuel cell are disclosed. The system includes: a fuel cell configured to receive a fuel gas and an oxidation gas and generate electric power; a recirculation line configured to circulate gas containing the fuel gas and connected to a fuel electrode of the fuel cell; a discharge valve provided in the recirculation line and configured to allow the gas to be discharged to the outside when open; a discharge amount estimator configured to estimate a discharge amount of the discharged gas based on a supply amount of the fuel gas supplied to the recirculation line, a consumption amount of the fuel gas consumed in the fuel cell, and a change in the amount of the gas in the recirculation line; an offset calculator configured to calculate the discharge amount of the gas estimated by the discharge amount estimator with the discharge valve closed, as a discharge offset; and a controller configured to control opening/closing of the discharge valve.

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 system capable of improving the chemical durability of a membrane electrode assembly by compensating for the amount of an antioxidant lost within the electrolyte membrane or electrode of the fuel cell stack in such a manner that the antioxidant is provided from an antioxidant supply device, provided in a fuel processing system and/or an air processing system, to a fuel cell stack, in preparation for a case where the antioxidant within the electrolyte membrane or electrode is lost due to the dissolution or migration characteristic of the antioxidant.

A fuel cell system capable of improving the chemical durability of a membrane electrode assembly by compensating for the amount of an antioxidant lost within the electrolyte membrane or electrode of the fuel cell stack in such a manner that the antioxidant is provided from an antioxidant supply device, provided in a fuel processing system and/or an air processing system, to a fuel cell stack, in preparation for a case where the antioxidant within the electrolyte membrane or electrode is lost due to the dissolution or migration characteristic of the antioxidant.

A cold start device for an exothermic hydrogen consumer such as a fuel cell, as well as a method for operating an exothermic hydrogen consumer with a metal hydride storage system. An exothermic hydrogen consumer such as a fuel cell with an efficient cold start device which can be brought into operation rapidly and. does not require a pressure tank is provided. The cold start device is available for an unlimited number of start-up procedures. At least one starter tank is filled with a metal hydride which has an equilibrium pressure for desorption of at least 100 kPa at a temperature of −40° C., as well as at least one operating tank which is filled with at least one metal hydride, which has an equilibrium pressure of <100 kPa at temperatures of <0° C., and wherein the starter tank is incorporated into the operating tank.

The invention relates to a method for operating a fuel cell system, in which method a supply of air to a fuel cell stack (20) is interrupted intermittently, in particular in the event of a standstill of the system, by means of a pressure-controlled shutoff valve (1), which comprises a valve element (4), which valve element can be moved back and forth between two end positions and is preloaded toward a sealing seat (3) by means of the spring force of a closing spring (2). According to the invention, in at least one of the two end positions, the valve element is held in the end position in question additionally by means of the magnetic force of an electromagnet (5) and/or of a permanent magnet (6), the electromagnet (5) and/or the permanent magnet (6) interacting with a magnetic or magnetizable part (7) of the valve element (4). The invention further relates to a shutoff valve (1) suitable for carrying out the method according to the invention and to a fuel cell stack (20) having at least one shutoff valve (1) according to the invention.

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.

In order to improve estimation accuracy of a purging amount, a fuel cell system comprises a supply valve that controls a supply of an anode gas into an anode system, a purge valve that discharges an off-gas from the anode system, a pressure detecting unit configured to estimate or measures a pressure inside the anode system, and a purging amount estimating unit configured to estimate a purging amount of the off-gas discharged from the anode system through the purge valve based on a pressure change inside the anode system during a purge valve close duration in a supply valve open state and a pressure change inside the anode system during a purge valve close duration in a supply valve close state.

A redox flow battery includes a cell stack formed by stacking a plurality of battery cells, a positive electrolyte circulation mechanism configured to circulate a positive electrolyte in the cell stack, and a negative electrolyte circulation mechanism configure l to circulate a negative electrolyte in the cell stack. The redox flow battery includes a pressure difference forming mechanism that makes one of a pressure loss in a positive pipeline included in the positive electrolyte circulation mechanism and a pressure loss in a negative pipeline included in the negative electrolyte circulation mechanism greater than the other so that, when the positive electrolyte and the negative electrolyte are circulated in the cell stack, a pressure difference state is created where there is a difference between the pressures of the positive and negative electrolytes acting on a separation membrane included in each battery cell.