A membrane humidifier for a fuel cell is disclosed. The membrane includes a middle case in which a plurality of hollow fiber membranes are accommodated; a cap case coupled to the middle case; a potting part formed at the end portions of the plurality of hollow fiber membranes; and an assembling member disposed between the end portions of the cap case and the middle case, and simultaneously coupling, so as to be airtight, a gap between the cap case and the middle case and a gap between the cap case and the potting part.

A fuel cell system wherein the fuel cell comprises an electrolyte membrane; wherein the electrolyte membrane is a perfluorosulfonic acid (PFSA) membrane; wherein the controller has a data group showing a correlation between the current of the fuel cell and the temperature of the fuel cell which is necessary to keep a moisture content of the electrolyte membrane at a predetermined moisture content threshold or more; and wherein, when the temperature and voltage of the fuel cell become a predetermined first temperature threshold or more and a predetermined voltage threshold or more, respectively, the controller conducts a temperature dropping time power generation mode in which power generation is conducted while controlling the current of the fuel cell with reference to the data group, until the temperature of the fuel cell becomes a predetermined second temperature threshold which is lower than the first temperature threshold.

A linear time varying model predictive control (LTV-MPC) framework is developed for degradation-conscious control of automotive polymer electrolyte membrane (PEM) fuel cell systems. A reduced-order nonlinear model of the entire system is derived first. This nonlinear model is then successively linearized about the current operating point to obtain a linear model. The linear model is utilized to formulate the control problem using a rate-based MPC formulation. The controller objective is to ensure offset-free tracking of the power demand, while maximizing the overall system efficiency and enhancing its durability. To this end, the fuel consumption and the power loss due to auxiliary equipment are minimized. Moreover, the internal states of the fuel cell stack are constrained to avoid harmful conditions that are known stressors of the fuel cell components.

A humidifier for a fuel cell includes: a housing that includes a moist air supply port through which moist air is supplied, a moist air discharge port through which the moist air is discharged, and an inflow gas supply port through which inflow gas is supplied; a humidification unit provided in the housing to humidify the inflow gas by using the moist air; and a humidification amount adjusting unit to selectively adjust an amount of humidification of the inflow gas by the humidification unit based on a flow rate of the moist air supplied to the moist air supply port, thereby obtaining an advantageous effect of accurately adjusting the amount of humidification based on an operating condition of a fuel cell stack.

A method for determining membrane humidification by determining the membrane protonic resistance of a fuel cell stack at humidified conditions, and normalizing the base resistance of the fuel cell stack against the base resistance of a reference fuel cell stack.

A fuel cell system includes: an external load connected to a fuel cell; an electric power adjusting unit configured to adjust a generated electric power of the fuel cell in accordance with electric power consumption of the external load; a humidity control unit configured to control humidity of an electrolyte membrane in the fuel cell on the basis of the generated electric power of the fuel cell; an output voltage detecting unit configured to detect an output voltage of the fuel cell; and a cross leakage determining unit configured to cause the humidity control unit to increase the humidity of the electrolyte membrane when the fuel cell generates the electric power, the cross leakage determining unit being configured to determine whether a cross leakage amount increases or not on the basis of a change in the output voltage at that time.

A fuel cell system for supplying anode gas and cathode gas to a fuel cell and causing the fuel cell to generate power according to a load includes a component that circulates discharged gas of either the anode gas or the cathode gas discharged from the fuel cell to the fuel cell. The fuel cell system includes a power generation control unit that controls a power generation state of the fuel cell on the basis of the load, a freezing prediction unit that predicts the freezing of the component on the basis of a temperature of the fuel cell system. The fuel cell system includes an operation execution unit that executes a warm-up operation without stopping the fuel cell system or after the stop of the fuel cell system in the case of receiving a stop command of the fuel cell system when the freezing of the component is predicted.

A fuel cell system for generating power by supplying anode gas and cathode gas to a fuel cell, comprising a compressor for supplying the cathode gas to the fuel cell, a pulsating operation unit causing a pressure of the anode gas to pulsate based on an operation state of the fuel cell system, a first target pressure setting unit setting a first target pressure of the cathode gas based on a request of the fuel cell, a second target pressure setting unit setting a second target pressure of the cathode gas for keeping a differential pressure in the fuel cell to be within a permissible differential pressure range according to the pressure of the anode gas in the fuel cell, and a compressor control unit controlling the compressor based on the first target pressure and the second target pressure. The second target pressure setting unit sets the second target pressure based on an upper limit target pressure in pulsation on the pulsation of the pressure of the anode gas.

A device intended to generate electricity includes a planar fuel cell having: cells each provided with an anode and a cathode associated with a membrane, and a first face and a second face opposite to the first face, the first face being arranged on the side with the anodes of the fuel cell and the second face being arranged on the side with the cathodes of the fuel cell. Furthermore, this device includes a system configured to generate a first air flow intended to cooperate thermally with the first face, and configured to generate a second air flow intended to cooperate with the second face to ensure the supply of oxidizer to the cathodes of the fuel cell.

A fuel cell system of the present invention can suppress an excessively wet or dry state of a fuel cell stack so as to thereby ensure the durability of the fuel cell stack. The fuel cell system supplies an oxidant gas with a reduced flow rate per unit time and for a long time period if the rate of voltage decrease of the stack becomes faster than a threshold rate, and supplies the oxidant gas with an increased flow rate per unit time and for a short time period if the rate of voltage decrease becomes slower than a threshold rate.