An apparatus for estimating an amount of condensed water in an anode of a fuel cell system includes: an initial anode water vapor amount calculation unit to calculate an initial amount of water vapor in the anode of a fuel cell upon startup, an anode diffusion amount calculation unit to calculate an amount of H.sub.2O diffused from a cathode to the anode, a purge amount calculation unit to calculate an amount of water vapor discharged upon gas purging in the anode, a recirculation amount calculation unit to calculate the amount of water vapor recirculated to the anode, and a condensed water amount determination and water level estimation unit to calculate the actual amount of water vapor in the anode based on values calculated using these units and to calculate the amount of condensed water in a water trap.

The invention relates to a media management plate (1) for a fuel cell assembly (5), a fuel cell system (10) comprising the media management plate and a fuel cell assembly, and a method of operating a fuel cell system (10) comprising a fuel cell assembly (5) and the media management plate (1). All lines for supplying and discharging the fuel cell media and all devices necessary for treating the fuel cell media are integrated in the media management plate (1). The media management plate (1) can be heated by means of coolant and is functional both when oriented vertically and horizontally.

The invention relates to a media management plate (1) for a fuel cell assembly (5), a fuel cell system (10) comprising the media management plate and a fuel cell assembly, and a method of operating a fuel cell system (10) comprising a fuel cell assembly (5) and the media management plate (1). All lines for supplying and discharging the fuel cell media and all devices necessary for treating the fuel cell media are integrated in the media management plate (1). The media management plate (1) can be heated by means of coolant and is functional both when oriented vertically and horizontally.

The present disclosure provides a fuel cell stack, a fuel cell system and a method for controlling a fuel cell stack, which can reduce obstruction of reactive gas fluid channels caused by freezing of retained water, while allowing size to be reduced. The fuel cell stack of the disclosure comprises water storage units that are formed between every two adjacent fuel cell unit cells, surrounded by the adjacent separators, the wall members and the gaskets, and that communicate with the reactive gas discharge manifold via the gaps of the wall members. The fuel cell system of the disclosure controls either or both the valve and compressor in a reactive gas supply channel and/or the valve in a reactive gas discharge channel, to cause liquid water retained in the water storage units to be discharged out of the fuel cell stack. The controlling method of the disclosure includes reducing the pressure in and scavenging the interior of the reactive gas discharge manifold, to cause the liquid water that has been discharged into the reactive gas discharge manifold to be discharged out of the fuel cell stack.

The present disclosure provides a fuel cell stack, a fuel cell system and a method for controlling a fuel cell stack, which can reduce obstruction of reactive gas fluid channels caused by freezing of retained water, while allowing size to be reduced. The fuel cell stack of the disclosure comprises water storage units that are formed between every two adjacent fuel cell unit cells, surrounded by the adjacent separators, the wall members and the gaskets, and that communicate with the reactive gas discharge manifold via the gaps of the wall members. The fuel cell system of the disclosure controls either or both the valve and compressor in a reactive gas supply channel and/or the valve in a reactive gas discharge channel, to cause liquid water retained in the water storage units to be discharged out of the fuel cell stack. The controlling method of the disclosure includes reducing the pressure in and scavenging the interior of the reactive gas discharge manifold, to cause the liquid water that has been discharged into the reactive gas discharge manifold to be discharged out of the fuel cell stack.

A catalyst deterioration suppression device includes: a first device obtaining a fuel cell voltage V (=catalyst voltage V.sub.cat) as a variable to estimate a response speed (time constant τ) at which a coverage ratio of an oxide film of catalyst particles contained in a fuel cell cathode changes; a second device reading out a time constant τ.sub.t corresponding to the voltage V at a current time t from a pre-made map A representing a relationship between the voltage V and the time constant τ and corresponding to the catalyst particles; a third device generating a continuous-time type dynamic filter F(s, τ) by using the time constant τ.sub.t and converting the continuous-time type dynamic filter F(s, τ) to a discrete-time type dynamic filter F(z, τ); and a fourth device inputting a target voltage Vr to the discrete-time type dynamic filter F(z, τ) and outputting a corrected target voltage V.sub.r-fil.

A catalyst deterioration suppression device includes: a first device obtaining a fuel cell voltage V (=catalyst voltage V.sub.cat) as a variable to estimate a response speed (time constant τ) at which a coverage ratio of an oxide film of catalyst particles contained in a fuel cell cathode changes; a second device reading out a time constant τ.sub.t corresponding to the voltage V at a current time t from a pre-made map A representing a relationship between the voltage V and the time constant τ and corresponding to the catalyst particles; a third device generating a continuous-time type dynamic filter F(s, τ) by using the time constant τ.sub.t and converting the continuous-time type dynamic filter F(s, τ) to a discrete-time type dynamic filter F(z, τ); and a fourth device inputting a target voltage Vr to the discrete-time type dynamic filter F(z, τ) and outputting a corrected target voltage V.sub.r-fil.

The present invention relates to a fuel cell system and a control method for the same, it may be configured to include a plurality of stacks connected in series with each other, and supply moisture from one or more stacks of the plurality of stacks to one or more other stacks according to an operation condition of each of the plurality of stacks, and it has an advantage of improving an operation performance by uniformly forming the humidity condition of each of the plurality of stacks.

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.

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.