WO2008119495A1 - Device for the operation of a fuel cell system - Google Patents
Device for the operation of a fuel cell system Download PDFInfo
- Publication number
- WO2008119495A1 WO2008119495A1 PCT/EP2008/002401 EP2008002401W WO2008119495A1 WO 2008119495 A1 WO2008119495 A1 WO 2008119495A1 EP 2008002401 W EP2008002401 W EP 2008002401W WO 2008119495 A1 WO2008119495 A1 WO 2008119495A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- fuel cell
- cathode
- bypass
- humidifier
- line
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
- H01M8/04119—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with simultaneous supply or evacuation of electrolyte; Humidifying or dehumidifying
- H01M8/04126—Humidifying
- H01M8/04141—Humidifying by water containing exhaust gases
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
- H01M8/04119—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with simultaneous supply or evacuation of electrolyte; Humidifying or dehumidifying
- H01M8/04126—Humidifying
- H01M8/04149—Humidifying by diffusion, e.g. making use of membranes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
- H01M8/04492—Humidity; Ambient humidity; Water content
- H01M8/04507—Humidity; Ambient humidity; Water content of cathode reactants at the inlet or inside the fuel cell
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
- H01M8/04492—Humidity; Ambient humidity; Water content
- H01M8/04522—Humidity; Ambient humidity; Water content of cathode exhausts
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
- H01M8/04746—Pressure; Flow
- H01M8/04776—Pressure; Flow at auxiliary devices, e.g. reformer, compressor, burner
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
- H01M8/04828—Humidity; Water content
- H01M8/04835—Humidity; Water content of fuel cell reactants
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
- H01M8/241—Grouping of fuel cells, e.g. stacking of fuel cells with solid or matrix-supported electrolytes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Definitions
- the invention relates to an apparatus for operating a fuel cell system, comprising a fuel cell stack for generating electrical energy, wherein the fuel cell stack has a cathode inlet line for supplying a gaseous oxidant and a cathode outlet line for discharging a cathode exhaust gas, wherein in the cathode inlet line and in the Kathodenauslass- each direction a moisture sensor is arranged.
- the fuel cell system serves, for example, to supply energy to an electromotive drive in a motor vehicle.
- PEMFC Proton Exchange Membrane Fuel Cell
- PEFC Proton Exchange Fuel Cell
- a solid poly ⁇ mermembran of a proton conducting ionomer (PEM), such as Nafion is used as the electrolyte.
- PEM proton conducting ionomer
- the polymer membrane is coated on both sides with an electrode material which consists of a mixture of carbon with a metallic catalyst.
- the metallic catalyst is usually platinum and / or ruthenium. In order to achieve the proton conductivity required for the efficient generation of electricity, maintain membrane, it must be operated in a predetermined range of humidity.
- DE 102 46 168 A1 proposes a device for operating a fuel cell system with a fuel cell stack, in which the water vapor concentration of an oxygen-containing gas fed in via a cathode inlet line and a cathode exhaust gas discharged via a cathode outlet line is monitored by means of respectively associated moisture sensors, in order to return a portion of the water vapor-containing cathode exhaust gas to the cathode inlet line as a function of the measurement result.
- a critical drying of the polymer membrane can be reliably avoided in this way.
- the disadvantage is that due to the return of the cathode exhaust gas increasingly inert constituents can accumulate on the electrode surface, which ultimately has a reduction in the efficiency of E- lektrizticianserzeugung result.
- German Laid-Open Application DE 10 2006 022 864 A1 discloses a fuel cell system comprising a fuel cell stack, a cathode inlet line for supplying an oxidizing agent, a cathode outlet line for discharging a cathode exhaust gas, moisture sensors in the cathode inlet line and / or in the cathode outlet line, a humidifier for regulating the humidity the supplied oxidizing agent and a bypass line, wherein the bypass line for controlled bypassing of the Be ⁇ humidifier in response to the sensor signals of Feuch ⁇ activity sensors is used.
- German laid-open specification DE 102 19 626 A1 describes an electronic control system for diverting gas past the humidifier to a fuel cell stack. Depending on the sensor signals of the humidity sensor, the electronic control system controls whether the supplied gas passes through the humidifier or through the bypass line. tion is passed through without humidification to the fuel cell. When the humidity detected by the humidity sensor exceeds a first predetermined level or drops below a second predetermined level, the proportion of the gas being diverted is varied using the bypass line.
- German Offenlegungsschriften DE 10 2006 022 863 A1 and DE 10 2004 005 446 A1 describe further fuel cell systems in which the moisture of the supplied oxidizing agent is monitored and controlled by means of moisture sensors.
- Object of the present invention is to develop a device of the type mentioned in such a way that it allows a regulation of the water vapor concentration in a fuel cell stack regardless of a return of the water vapor-containing cathode exhaust gas.
- the apparatus for operating a fuel cell system comprises a fuel cell stack for generating electrical energy, wherein the fuel cell stack has a Kathodeneinlass Gustav for supplying a gaseous oxidizing agent and a cathode outlet for taking out a cathode exhaust gas, wherein in the Kathodeneinlass- line and in the Kathodenauslass admir in each case a moisture sensor is arranged ,
- a humidifier for regulating the water vapor concentration of the supplied gaseous oxide is additionally provided. provided, wherein a bypass line for the controlled bypass of the humidifier for the gaseous oxidizing agent to be humidified and a further bypass line for the controlled bypass of the humidifier for the cathode exhaust gas in dependence of the sensor signals of the humidity sensors is present.
- the humidifier is, in particular, a so-called gas-to-gas humidifier, in which a water vapor-containing humidifier gas flows along a hydrophilic or selective membrane, for example of polyphenylsulfone (PPSU) or cation, countercurrent to the humidifier humidifying gaseous oxidizer is passed.
- the humidifier gas used is, for example, the steam-saturated cathode exhaust gas of the fuel cell stack.
- the adjustment of the water vapor concentration can be done by adjusting the opening angle of a function of the sensor signals of the humidity sensor operated bypass valve, which is arranged in a bypass line of the humidifier.
- the bypass valve which is designed, for example, as a normally open control flap valve, in this case allows a targeted bridging of the volume flow between the inlet and outlet side of the humidifier, thus ultimately a change in the humidification performance.
- Such bypass lines are provided for the humidifier gas and the operating gas to be humidified.
- a central control device by evaluating the sensor signals, to determine a humidification quantity ⁇ representing the current water vapor concentration and to set it by suitable actuation of the bypass valves in accordance with a predetermined desired value.
- the setpoint is advantageously set such that an optimum for the operation of the fuel cell stack water vapor concentration is maintained.
- the moisture buffering effect of the fuel cell stack can be estimated based on a differential pressure measurement between the cathode inlet line and the cathode outlet line. Therefore, a total of two humidity sensors are present, with the Befeuchtungst ⁇ results as the difference of the sensor signals of the two humidity sensors.
- the fuel cell system is used in a motor vehicle, it is advantageous if the driver is informed of an impermissible operating state of the fuel cell system due to a too low moisture content of the polymer membrane.
- the output of a driver warning takes place when the absolute value deviation between the determined Befeuchtungsiere ⁇ and the predetermined setpoint exceeds a safety value to be maintained.
- FIGURE shows an embodiment of the device according to the invention for operating a fuel cell system.
- the fuel cell system 10 comprises a fuel cell stack 11 for generating electrical energy, the fuel cell stack 11 consisting of a layered arrangement of individual fuel cells 12.
- the fuel cell 12 is of the so-called Proton Exchange Membrane Fuel Cell (PEMFC) or Proton Exchange Fuel Cell (PEFC) type.
- PEMFC Proton Exchange Membrane Fuel Cell
- PEFC Proton Exchange Fuel Cell
- Such a fuel Cell 12 has an anode flow field 12a and a cathode flow field 12b, the two flow fields being separated by an electrolyte in the form of a Nafion polymer membrane (PEM).
- the polymer membrane is coated on both sides with an electrode material which consists of a mixture of carbon with a metallic catalyst.
- the metallic catalyst is platinum or a platinum and ruthenium-containing alloy.
- the anode flow field 12a is supplied via an anode inlet line 13 with a hydrogen-containing fuel 14 provided by a high-pressure tank or a reformer.
- the hydrogen-containing fuel 14 may be pure hydrogen gas.
- the supply line 13 is shut off by means of an electromagnetic valve 15 to preclude an undesirable release of hydrogen gas into the environment.
- the anode exhaust gas formed in the anode flow field 12a is discharged through an anode outlet 20 either directly to atmosphere or at least partly recirculated via a Anoden literally utilizat 21, which opens into the anode inlet line 13 of the fuel cell 12 into the anode flow field 12a ⁇ .
- the volume flow of the recirculated anode exhaust gas can be controlled by means of an electrically operable throttle valve 22 arranged in the anode purge line 21.
- a gaseous oxidizing agent 24 in the form of compressed air is fed to the cathode flow field 12b via a cathode inlet line 23.
- the compression of the air which is taken from the outside atmosphere via an air filter system, takes place here by means of an electrically powered air supply unit 25a, for example by means of a compressor or turbocharger.
- the air filter system has, in addition to a chemical and / or mechanical particulate filter, a silencer for reducing the noise during operation of the air supply unit 25a.
- the fuel cell system 10 additionally includes a humidifier 30 for controlling the water vapor concentration of the supplied gaseous oxidant 24.
- the humidifier 30 is a so-called gas-to-gas humidifier in which a water vapor-containing humidifier gas along a hydrophilic or selective membrane, For example, from polyphenylsulfone (PPSU) or Nafion, is passed in countercurrent to the gaseous oxidant 24 to be humidified.
- the humidifier gas used is the water-vapor-saturated cathode exhaust gas of the fuel cell stack 11 which is led out via a cathode outlet line 31, which, after passing through the humidifier 30, is expanded via an expander 25b connected to the air supply unit 25a and discharged to the environment.
- bypass lines 32a, 32b are provided for controlled bypassing of the humidifier 30, wherein an electrically actuated bypass valve valve 33a, 33b is respectively arranged in the bypass lines 32a, 32b.
- the bypass valves 33a, 33b in this case allow a targeted bridging of the volume flow between the inlet and outlet side of the humidifier 30, thus ultimately a change in the humidifying performance.
- a cooling device 12c For cooling the fuel cell 12, a cooling device 12c is provided.
- the cooling device 12c is connected to ademit ⁇ tel Vietnameselauf 35 having an electrically operated pump 36 for circulating a circulating in the refrigerant circuit 35 refrigerant.
- the process heat arising during operation of the fuel cell 12 is dissipated via a process heat Coolant circuit 35 located radiator 37 delivered to the environment.
- a central control device, not shown, of the fuel cell system 10 evaluates the sensor signals of the humidity sensors 40, 41 arranged in the cathode inlet line 23 and the cathode outlet line 31 in order to determine a humidification quantity ⁇ representing the current water vapor concentration and to correspondingly actuate these by appropriate actuation of the bypass valves 33a, 33b to set a predetermined setpoint.
- a total of two humidity sensors 40 and 41 are present, wherein the Befeuchtungsish ⁇ results as a difference of the sensor signals of the two humidity sensors 40 and 41.
- the central control device causes the issuing of a driver warning when the absolute deviation between the determined Befeuchtungsiere ⁇ and the pre ⁇ give external command value exceeds a safety value to be maintained.
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Fuel Cell (AREA)
Abstract
Description
Vorrichtung zum Betreiben eines BrennstoffZeilensystems Apparatus for operating a fuel cell system
Die Erfindung bezieht sich auf eine Vorrichtung zum Betreiben eines Brennstoffzellensystems, mit einem Brennstoffzellensta- pel zur Erzeugung elektrischer Energie, wobei der Brennstoffzellenstapel eine Kathodeneinlassleitung zum Zuführen eines gasförmigen Oxidationsmittels sowie eine Kathodenauslasslei- tung zum Herausführen eines Kathodenabgases aufweist, wobei in der Kathodeneinlassleitung und in der Kathodenauslasslei- tung jeweils ein Feuchtigkeitssensor angeordnet ist.The invention relates to an apparatus for operating a fuel cell system, comprising a fuel cell stack for generating electrical energy, wherein the fuel cell stack has a cathode inlet line for supplying a gaseous oxidant and a cathode outlet line for discharging a cathode exhaust gas, wherein in the cathode inlet line and in the Kathodenauslass- each direction a moisture sensor is arranged.
Das Brennstoffzellensystem dient beispielsweise der Energieversorgung eines elektromotorischen Antriebs in einem Kraftfahrzeug.The fuel cell system serves, for example, to supply energy to an electromotive drive in a motor vehicle.
Ein im Kraftfahrzeugbereich gebräuchlicher Brennstoffzellen- typ stellt die so genannte Proton Exchange Membrane Fuel Cell (PEMFC) bzw. Proton Exchange Fuel Cell (PEFC) dar, die durch elektrochemische Reaktion eines wasserstoffhaltigen Brennstoffes mit einem sauerstoffhaltigen Oxidationsmittel elektrische Energie erzeugt. Als Elektrolyt dient eine feste Poly¬ mermembran aus einem Protonen leitenden Ionomer (PEM), beispielsweise Nafion. Die Polymermembran ist beidseitig mit einem Elektrodenmaterial beschichtet, das aus einer Mischung von Kohlenstoff mit einem metallischen Katalysator besteht. Bei dem metallischen Katalysator handelt es sich in der Regel um Platin und/oder Ruthenium. Um die zur effizienten Elektrizitätserzeugung erforderliche Protonenleitfähigkeit der PoIy- mermembran aufrechtzuerhalten, muss diese in einem vorgegebenen Feuchtigkeitsbereich betrieben werden.One common in the automotive field fuel cell type is the so-called Proton Exchange Membrane Fuel Cell (PEMFC) or Proton Exchange Fuel Cell (PEFC), which generates electrical energy by electrochemical reaction of a hydrogen-containing fuel with an oxygen-containing oxidant. A solid poly ¬ mermembran of a proton conducting ionomer (PEM), such as Nafion is used as the electrolyte. The polymer membrane is coated on both sides with an electrode material which consists of a mixture of carbon with a metallic catalyst. The metallic catalyst is usually platinum and / or ruthenium. In order to achieve the proton conductivity required for the efficient generation of electricity, maintain membrane, it must be operated in a predetermined range of humidity.
Vor diesem Hintergrund schlägt die DE 102 46 168 Al eine Vorrichtung zum Betreiben eines Brennstoffzellensystems mit einem Brennstoffzellenstapel vor, bei der die Wasserdampfkon- zentration eines über eine Kathodeneinlassleitung zugeführten sauerstoffhaltigen Gases sowie eines über eine Kathodenaus- lassleitung abgelassenen Kathodenabgases mittels jeweils zugehöriger Feuchtigkeitssensoren überwacht wird, um in Abhängigkeit des Messergebnisses einen Teil des wasserdampfhaltigen Kathodenabgases zur Kathodeneinlassleitung zurückzuführen. Ein kritisches Austrocknen der Polymermembran lässt sich auf diese Weise zuverlässig vermeiden. Nachteilig ist, dass sich aufgrund der Rückführung des Kathodenabgases vermehrt inerte Bestandteile auf der Elektrodenoberfläche anreichern können, was letztlich eine Verringerung der Effizienz der E- lektrizitätserzeugung zur Folge hat.Against this background, DE 102 46 168 A1 proposes a device for operating a fuel cell system with a fuel cell stack, in which the water vapor concentration of an oxygen-containing gas fed in via a cathode inlet line and a cathode exhaust gas discharged via a cathode outlet line is monitored by means of respectively associated moisture sensors, in order to return a portion of the water vapor-containing cathode exhaust gas to the cathode inlet line as a function of the measurement result. A critical drying of the polymer membrane can be reliably avoided in this way. The disadvantage is that due to the return of the cathode exhaust gas increasingly inert constituents can accumulate on the electrode surface, which ultimately has a reduction in the efficiency of E- lektrizitätserzeugung result.
Aus der deutschen Offenlegungsschrift DE 10 2006 022 864 Al ist ein Brennstoffzellensystem bekannt, das einen Brennstoffzellenstapel, eine Kathodeneinlassleitung zum Zuführen eines Oxidationsmittels, eine Kathodenauslassleitung zum Herausführen eines Kathodenabgases, Feuchtigkeitssensoren in der Kathodeneinlassleitung und/oder in der Kathodenauslassleitung, einen Befeuchter zum Regulieren der Feuchtigkeit des zugeführten Oxidationsmittels und eine Bypassleitung umfasst, wobei die Bypassleitung zur kontrollierten Umgehung des Be¬ feuchters in Abhängigkeit von den Sensorsignalen der Feuch¬ tigkeitssensoren dient.German Laid-Open Application DE 10 2006 022 864 A1 discloses a fuel cell system comprising a fuel cell stack, a cathode inlet line for supplying an oxidizing agent, a cathode outlet line for discharging a cathode exhaust gas, moisture sensors in the cathode inlet line and / or in the cathode outlet line, a humidifier for regulating the humidity the supplied oxidizing agent and a bypass line, wherein the bypass line for controlled bypassing of the Be ¬ humidifier in response to the sensor signals of Feuch ¬ activity sensors is used.
In der deutschen Offenlegungsschrift DE 102 19 626 Al wird eine elektronische Steuerung zur Umleitung von Gas am Be¬ feuchter vorbei zu einem Brennstoffzellenstapel beschrieben. In Abhängigkeit von den Sensorsignalen des Feuchtigkeitssensors regelt die elektronische Steuerung, ob das zugeführte Gas durch den Befeuchter hindurch oder durch die Bypasslei- tung hindurch ohne Befeuchtung zur Brennstoffzelle geleitet wird. Wenn die Feuchtigkeit, die durch den Feuchtigkeitssensor erfasst wird, ein erstes vorbestimmtes Niveau überschreitet oder unter ein zweites vorbestimmtes Niveau abfällt, wird der Anteil des Gases, der umgeleitet wird, unter Verwendung der Bypassleitung variiert.German laid-open specification DE 102 19 626 A1 describes an electronic control system for diverting gas past the humidifier to a fuel cell stack. Depending on the sensor signals of the humidity sensor, the electronic control system controls whether the supplied gas passes through the humidifier or through the bypass line. tion is passed through without humidification to the fuel cell. When the humidity detected by the humidity sensor exceeds a first predetermined level or drops below a second predetermined level, the proportion of the gas being diverted is varied using the bypass line.
In den deutschen Offenlegungsschriften DE 10 2006 022 863 Al und DE 10 2004 005 446 Al werden weitere Brennstoffzellensys- teme beschrieben, in denen die Feuchtigkeit des zugeführten Oxidationsmittels mittels Feuchtigkeitssensoren überwacht und gesteuert wird.German Offenlegungsschriften DE 10 2006 022 863 A1 and DE 10 2004 005 446 A1 describe further fuel cell systems in which the moisture of the supplied oxidizing agent is monitored and controlled by means of moisture sensors.
In der Patentanmeldung US 2001/0010875 Al wird ein Befeuchtungssystem für Oxidationsmittel beschrieben, bei dem verschiedene Bypassvariationen einstellbar sind.In the patent application US 2001/0010875 Al a humidification system for oxidizing agent is described in which various bypass variations are adjustable.
Aufgabe der vorliegenden Erfindung ist es, eine Vorrichtung der eingangs genannten Art derart weiterzubilden, dass diese eine Regulierung der Wasserdampfkonzentration in einem Brennstoffzellenstapel unabhängig von einer Rückführung des wasserdampfhaltigen Kathodenabgases ermöglicht.Object of the present invention is to develop a device of the type mentioned in such a way that it allows a regulation of the water vapor concentration in a fuel cell stack regardless of a return of the water vapor-containing cathode exhaust gas.
Diese Aufgabe wird durch eine Vorrichtung mit den Merkmalen des Patentanspruchs 1 gelöst.This object is achieved by a device having the features of patent claim 1.
Die Vorrichtung zum Betreiben eines Brennstoffzellensystems umfasst einen Brennstoffzellenstapel zur Erzeugung elektrischer Energie, wobei der Brennstoffzellenstapel eine Katho- deneinlassleitung zum Zuführen eines gasförmigen Oxidationsmittels sowie eine Kathodenauslassleitung zum Herausführen eines Kathodenabgases aufweist, wobei in der Kathodeneinlass- leitung und in der Kathodenauslassleitung jeweils ein Feuchtigkeitssensor angeordnet ist.The apparatus for operating a fuel cell system comprises a fuel cell stack for generating electrical energy, wherein the fuel cell stack has a Kathodeneinlassleitung for supplying a gaseous oxidizing agent and a cathode outlet for taking out a cathode exhaust gas, wherein in the Kathodeneinlass- line and in the Kathodenauslassleitung in each case a moisture sensor is arranged ,
Erfindungsgemäß ist zusätzlich ein Befeuchter zur Regulierung der Wasserdampfkonzentration des zugeführten gasförmigen Oxi- dationsmittels vorgesehen, wobei eine Bypassleitung zur kontrollierten Umgehung des Befeuchters für das zu befeuchtende gasförmige Oxidationsmittel und eine weitere Bypassleitung zur kontrollierten Umgehung des Befeuchters für das Kathodenabgas in Abhängigkeit der Sensorsignale der Feuchtigkeitssensoren vorhanden ist.According to the invention, a humidifier for regulating the water vapor concentration of the supplied gaseous oxide is additionally provided. provided, wherein a bypass line for the controlled bypass of the humidifier for the gaseous oxidizing agent to be humidified and a further bypass line for the controlled bypass of the humidifier for the cathode exhaust gas in dependence of the sensor signals of the humidity sensors is present.
Bei dem Befeuchter handelt es sich insbesondere um einen so genannten Gas-zu-Gas-Befeuchter, bei dem ein wasserdampfhal- tiges Befeuchtergas entlang einer hydrophilen bzw. selektiven Membran, beispielsweise aus Polyphenylsulfon (PPSU) oder Na- fion, im Gegenstrom zu dem zu befeuchtenden gasförmigen Oxidationsmittel geleitet wird. Als Befeuchtergas wird beispielsweise das wasserdampfgesättigte Kathodenabgas des Brennstoffzellenstapels genutzt.The humidifier is, in particular, a so-called gas-to-gas humidifier, in which a water vapor-containing humidifier gas flows along a hydrophilic or selective membrane, for example of polyphenylsulfone (PPSU) or cation, countercurrent to the humidifier humidifying gaseous oxidizer is passed. The humidifier gas used is, for example, the steam-saturated cathode exhaust gas of the fuel cell stack.
Vorteilhafte Ausführungen der erfindungsgemäßen Vorrichtung gehen aus den Unteransprüchen hervor.Advantageous embodiments of the device according to the invention will become apparent from the dependent claims.
Die Einstellung der Wasserdampfkonzentration kann durch Anpassung des Öffnungswinkels eines in Abhängigkeit der Sensorsignale des Feuchtigkeitssensors betätigten Bypassventils, das in einer Bypassleitung des Befeuchters angeordnet ist, erfolgen. Das Bypassventil, das beispielsweise als stromlos offenes Regelklappenventil ausgebildet ist, erlaubt hierbei eine gezielte Überbrückung des Volumenflusses zwischen Ein- und Ausgangsseite des Befeuchters, mithin also letztlich eine Veränderung der Befeuchtungsleistung. Derartige Bypassleitun- gen sind für das Befeuchtergas und das zu befeuchtende Betriebsgas vorgesehen.The adjustment of the water vapor concentration can be done by adjusting the opening angle of a function of the sensor signals of the humidity sensor operated bypass valve, which is arranged in a bypass line of the humidifier. The bypass valve, which is designed, for example, as a normally open control flap valve, in this case allows a targeted bridging of the volume flow between the inlet and outlet side of the humidifier, thus ultimately a change in the humidification performance. Such bypass lines are provided for the humidifier gas and the operating gas to be humidified.
Hierbei besteht die Möglichkeit, dass eine zentrale Steuereinrichtung durch Auswertung der Sensorsignale eine die aktuelle Wasserdampfkonzentration wiedergebende Befeuchtungsgröße λ ermittelt und diese durch geeignete Betätigung der Bypass- ventile entsprechend einem vorgegebenen Sollwert einstellt. Der Sollwert wird vorteilhafterweise derart vorgegeben, dass eine für den Betrieb des Brennstoffzellenstapels optimale Wasserdampfkonzentration eingehalten wird.In this case, it is possible for a central control device, by evaluating the sensor signals, to determine a humidification quantity λ representing the current water vapor concentration and to set it by suitable actuation of the bypass valves in accordance with a predetermined desired value. The setpoint is advantageously set such that an optimum for the operation of the fuel cell stack water vapor concentration is maintained.
Um im Falle dynamischer Lastwechsel eine genaue Einstellung der Wasserdampfkonzentration sicherzustellen, ist es erforderlich, die Feuchtigkeit puffernde Wirkung des Brennstoffzellenstapels aufgrund des darin vorhandenen Prozesswassers zu berücksichtigen. Die Feuchtigkeit puffernde Wirkung des Brennstoffzellenstapels lässt sich auf Grundlage einer Differenzdruckmessung zwischen der Kathodeneinlassleitung und der Kathodenauslassleitung abschätzen. Daher sind insgesamt zwei Feuchtigkeitssensoren vorhanden, wobei sich die Befeuchtungsgröße λ als Differenz der Sensorsignale der beiden Feuchtigkeitssensoren ergibt.In order to ensure a precise adjustment of the water vapor concentration in the case of dynamic load changes, it is necessary to take into account the moisture buffering effect of the fuel cell stack due to the process water present therein. The moisture buffering effect of the fuel cell stack can be estimated based on a differential pressure measurement between the cathode inlet line and the cathode outlet line. Therefore, a total of two humidity sensors are present, with the Befeuchtungsgröße λ results as the difference of the sensor signals of the two humidity sensors.
Wird das Brennstoffzellensystem in einem Kraftfahrzeug eingesetzt, ist es von Vorteil, wenn der Fahrer auf einen unzulässigen Betriebszustand des Brennstoffzellensystems aufgrund einer zu geringen Feuchtigkeit der Polymermembran hingewiesen wird. Hierzu erfolgt die Ausgabe einer Fahrerwarnung, wenn die betragsmäßige Abweichung zwischen der ermittelten Befeuchtungsgröße λ und dem vorgegebenen Sollwert einen einzuhaltenden Sicherheitswert überschreitet.If the fuel cell system is used in a motor vehicle, it is advantageous if the driver is informed of an impermissible operating state of the fuel cell system due to a too low moisture content of the polymer membrane. For this purpose, the output of a driver warning takes place when the absolute value deviation between the determined Befeuchtungsgröße λ and the predetermined setpoint exceeds a safety value to be maintained.
Die erfindungsgemäße Vorrichtung wird im Folgenden anhand der beigefügten Zeichnung näher erläutert. Die einzige Figur zeigt ein Ausführungsbeispiel der erfindungsgemäßen Vorrichtung zum Betreiben eines Brennstoffzellensystems .The device according to the invention is explained in more detail below with reference to the accompanying drawings. The single FIGURE shows an embodiment of the device according to the invention for operating a fuel cell system.
Das Brennstoffzellensystem 10 umfasst einen Brennstoffzellen- stapel 11 zur Erzeugung elektrischer Energie, wobei der Brennstoffzellenstapel 11 aus einer schichtweisen Anordnung einzelner Brennstoffzellen 12 besteht.The fuel cell system 10 comprises a fuel cell stack 11 for generating electrical energy, the fuel cell stack 11 consisting of a layered arrangement of individual fuel cells 12.
Beispielsgemäß ist die Brennstoffzelle 12 vom Typ einer so genannten Proton Exchange Membrane Fuel Cell (PEMFC) bzw. Proton Exchange Fuel Cell (PEFC) . Eine derartige Brennstoff- zelle 12 weist ein Anodenströmungsfeld 12a und ein Kathoden- strömungsfeld 12b auf, wobei die beiden Strömungsfelder durch einen Elektrolyten in Gestalt einer aus Nafion bestehenden Polymermembran (PEM) voneinander getrennt sind. Die Polymer- membran ist beidseitig mit einem Elektrodenmaterial beschichtet, das aus einer Mischung von Kohlenstoff mit einem metallischen Katalysator besteht. Bei dem metallischen Katalysator handelt es sich um Platin oder eine Platin und Ruthenium enthaltende Legierung.By way of example, the fuel cell 12 is of the so-called Proton Exchange Membrane Fuel Cell (PEMFC) or Proton Exchange Fuel Cell (PEFC) type. Such a fuel Cell 12 has an anode flow field 12a and a cathode flow field 12b, the two flow fields being separated by an electrolyte in the form of a Nafion polymer membrane (PEM). The polymer membrane is coated on both sides with an electrode material which consists of a mixture of carbon with a metallic catalyst. The metallic catalyst is platinum or a platinum and ruthenium-containing alloy.
Zum Betrieb der Brennstoffzelle 12 wird dem Anodenströmungsfeld 12a über eine Anodeneinlassleitung 13 ein wasserstoff- haltiger Brennstoff 14 zugeführt, der von Seiten eines Hochdrucktanks oder eines Reformers bereitgestellt wird. Bei dem wasserstoffhaltigen Brennstoff 14 kann es sich um reines Wasserstoffgas handeln.For operation of the fuel cell 12, the anode flow field 12a is supplied via an anode inlet line 13 with a hydrogen-containing fuel 14 provided by a high-pressure tank or a reformer. The hydrogen-containing fuel 14 may be pure hydrogen gas.
Ist das Brennstoffzellensystem 10 abgeschaltet, wird die Versorgungsleitung 13 mittels eines elektromagnetischen Ventils 15 abgesperrt, um eine unerwünschte Freisetzung von Wasserstoffgas in die Umgebung auszuschließen.If the fuel cell system 10 is turned off, the supply line 13 is shut off by means of an electromagnetic valve 15 to preclude an undesirable release of hydrogen gas into the environment.
Das im Anodenströmungsfeld 12a gebildete Anodenabgas wird ü- ber eine Anodenauslassleitung 20 entweder unmittelbar zur Umgebung hin abgelassen oder aber zumindest teilweise über eine Anodenspülleitung 21, die in die Anodeneinlassleitung 13 der Brennstoffzelle 12 mündet, in das Anodenströmungsfeld 12a zu¬ rückgeführt. Der Volumenstrom des zurückgeführten Anodenabgases lässt sich mittels eines in der Anodenspülleitung 21 angeordneten elektrisch betätigbaren Drosselklappenventils 22 steuern .The anode exhaust gas formed in the anode flow field 12a is discharged through an anode outlet 20 either directly to atmosphere or at least partly recirculated via a Anodenspülleitung 21, which opens into the anode inlet line 13 of the fuel cell 12 into the anode flow field 12a ¬. The volume flow of the recirculated anode exhaust gas can be controlled by means of an electrically operable throttle valve 22 arranged in the anode purge line 21.
Gleichzeitig wird dem Kathodenströmungsfeld 12b über eine Ka- thodeneinlassleitung 23 ein gasförmiges Oxidationsmittel 24 in Form komprimierter Luft zugeführt. Die Komprimierung der Luft, die über ein Luftfiltersystem aus der Außenatmosphäre entnommen wird, erfolgt hierbei mittels einer elektrisch be- triebenen Luftversorgungseinheit 25a, beispielsweise mittels eines Kompressors bzw. Turboladers. Das Luftfiltersystem weist unter anderem neben einem chemischen und/oder mechanischen Partikelfilter einen Schalldämpfer zur Verringerung des Geräuschs beim Betrieb der Luftversorgungseinheit 25a auf.At the same time, a gaseous oxidizing agent 24 in the form of compressed air is fed to the cathode flow field 12b via a cathode inlet line 23. The compression of the air, which is taken from the outside atmosphere via an air filter system, takes place here by means of an electrically powered air supply unit 25a, for example by means of a compressor or turbocharger. The air filter system has, in addition to a chemical and / or mechanical particulate filter, a silencer for reducing the noise during operation of the air supply unit 25a.
Das BrennstoffZeilensystem 10 umfasst zusätzlich einen Befeuchter 30 zur Regulierung der Wasserdampfkonzentration des zugeführten gasförmigen Oxidationsmittels 24. Bei dem Befeuchter 30 handelt es sich um einen so genannten Gas-zu-Gas- Befeuchter, bei dem ein wasserdampfhaltiges Befeuchtergas entlang einer hydrophilen bzw. selektiven Membran, beispielsweise aus Polyphenylsulfon (PPSU) oder Nafion, im Gegenstrom zu dem zu befeuchtenden gasförmigen Oxidationsmittel 24 geleitet wird. Als Befeuchtergas wird das über eine Kathoden- auslassleitung 31 herausgeführte wasserdampfgesättigte Kathodenabgas des Brennstoffzellenstapels 11 verwendet, wobei dieses nach Durchlaufen des Befeuchters 30 über einen mit dem Luftversorgungseinheit 25a verbundenen Expander 25b entspannt und zur Umgebung hin abgelassen wird.The fuel cell system 10 additionally includes a humidifier 30 for controlling the water vapor concentration of the supplied gaseous oxidant 24. The humidifier 30 is a so-called gas-to-gas humidifier in which a water vapor-containing humidifier gas along a hydrophilic or selective membrane, For example, from polyphenylsulfone (PPSU) or Nafion, is passed in countercurrent to the gaseous oxidant 24 to be humidified. The humidifier gas used is the water-vapor-saturated cathode exhaust gas of the fuel cell stack 11 which is led out via a cathode outlet line 31, which, after passing through the humidifier 30, is expanded via an expander 25b connected to the air supply unit 25a and discharged to the environment.
Beispielsgemäß sind zwei Bypassleitung 32a, 32b zur kontrollierten Umgehung des Befeuchters 30 vorhanden, wobei in den Bypassleitungen 32a, 32b jeweils ein elektrisch betätigbares Bypassventilventil 33a, 33b angeordnet ist. Die Bypassventile 33a, 33b erlauben hierbei eine gezielte Überbrückung des Volumenflusses zwischen Ein- und Ausgangsseite des Befeuchters 30, mithin also letztlich eine Veränderung der Befeuchtungsleistung.By way of example, two bypass lines 32a, 32b are provided for controlled bypassing of the humidifier 30, wherein an electrically actuated bypass valve valve 33a, 33b is respectively arranged in the bypass lines 32a, 32b. The bypass valves 33a, 33b in this case allow a targeted bridging of the volume flow between the inlet and outlet side of the humidifier 30, thus ultimately a change in the humidifying performance.
Zur Kühlung der Brennstoffzelle 12 ist eine Kühleinrichtung 12c vorgesehen. Die Kühleinrichtung 12c ist an einen Kühlmit¬ telkreislauf 35 angeschlossen, der eine elektrisch betriebene Förderpumpe 36 zum Umwälzen eines in dem Kühlmittelkreislauf 35 zirkulierenden Kühlmittels aufweist. Die beim Betrieb der Brennstoffzelle 12 anfallende Prozesswärme wird über einen im Kühlmittelkreislauf 35 befindlichen Radiator 37 an die Umgebung abgegeben.For cooling the fuel cell 12, a cooling device 12c is provided. The cooling device 12c is connected to a Kühlmit ¬ telkreislauf 35 having an electrically operated pump 36 for circulating a circulating in the refrigerant circuit 35 refrigerant. The process heat arising during operation of the fuel cell 12 is dissipated via a process heat Coolant circuit 35 located radiator 37 delivered to the environment.
Eine nicht dargestellte zentrale Steuereinrichtung des BrennstoffZeilensystems 10 wertet die Sensorsignale der in der Ka- thodeneinlassleitung 23 und der Kathodenauslassleitung 31 angeordneten Feuchtigkeitssensoren 40, 41 aus, um eine die aktuelle Wasserdampfkonzentration wiedergebende Befeuchtungsgröße λ zu ermitteln und diese durch geeignete Betätigung der Bypassventile 33a, 33b entsprechend einem vorgegebenen Sollwert einzustellen. Wie erwähnt sind insgesamt zwei Feuchtigkeitssensoren 40 und 41 vorhanden, wobei sich die Befeuchtungsgröße λ als Differenz der Sensorsignale der beiden Feuchtigkeitssensoren 40 und 41 ergibt.A central control device, not shown, of the fuel cell system 10 evaluates the sensor signals of the humidity sensors 40, 41 arranged in the cathode inlet line 23 and the cathode outlet line 31 in order to determine a humidification quantity λ representing the current water vapor concentration and to correspondingly actuate these by appropriate actuation of the bypass valves 33a, 33b to set a predetermined setpoint. As mentioned, a total of two humidity sensors 40 and 41 are present, wherein the Befeuchtungsgröße λ results as a difference of the sensor signals of the two humidity sensors 40 and 41.
Um den Fahrer auf einen unzulässigen Betriebszustand des BrennstoffZeilensystems 10 aufgrund einer zu geringen Feuchtigkeit der Polymermembran der Brennstoffzelle 12 hinzuweisen, ist gemäß einer beispielhaften Weiterbildung vorgesehen, dass die zentrale Steuereinrichtung die Ausgabe einer Fahrerwarnung veranlasst, wenn die betragsmäßige Abweichung zwischen der ermittelten Befeuchtungsgröße λ und dem vorgegebe¬ nen Sollwert einen einzuhaltenden Sicherheitswert überschreitet. In order to alert the driver to an inadmissible operating state of the fuel cell system 10 due to insufficient moisture of the polymer membrane of the fuel cell 12, it is provided according to an exemplary embodiment that the central control device causes the issuing of a driver warning when the absolute deviation between the determined Befeuchtungsgröße λ and the pre ¬ give external command value exceeds a safety value to be maintained.
BezugszeichenlisteLIST OF REFERENCE NUMBERS
Claims
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102007015955.4 | 2007-04-03 | ||
| DE102007015955.4A DE102007015955B4 (en) | 2007-04-03 | 2007-04-03 | Apparatus for operating a fuel cell system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2008119495A1 true WO2008119495A1 (en) | 2008-10-09 |
Family
ID=39587952
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2008/002401 Ceased WO2008119495A1 (en) | 2007-04-03 | 2008-03-27 | Device for the operation of a fuel cell system |
Country Status (2)
| Country | Link |
|---|---|
| DE (1) | DE102007015955B4 (en) |
| WO (1) | WO2008119495A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113224351A (en) * | 2020-01-21 | 2021-08-06 | 上海氢晨新能源科技有限公司 | Fuel cell stack humidity control system and method |
| CN115939460A (en) * | 2021-10-01 | 2023-04-07 | 洁能氏公司 | System and method for controlling and monitoring fuel cell stack using cathode exhaust humidity |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5389090B2 (en) * | 2011-03-31 | 2014-01-15 | 本田技研工業株式会社 | Fuel cell system |
| DE102013015509A1 (en) | 2013-09-19 | 2015-03-19 | Daimler Ag | Fuel cell system and method for operating a fuel cell system |
| DE102013021507A1 (en) | 2013-12-18 | 2015-06-18 | Daimler Ag | A fuel cell assembly |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000164231A (en) * | 1998-11-26 | 2000-06-16 | Toshiba Corp | Polymer electrolyte fuel cell system |
| US20010046616A1 (en) * | 2000-03-08 | 2001-11-29 | Mossman Alexander Douglas | Membrane exchange humidifier |
| DE10246168A1 (en) * | 2002-10-02 | 2004-04-15 | Daimlerchrysler Ag | Fuel cell has pumped feedback loop to control the water content based on input and output moisture sensors |
| US20060101994A1 (en) * | 2002-07-18 | 2006-05-18 | Daimlerchrysler Ag | Device and method for humidifying a gas flow |
| DE102006022864A1 (en) * | 2005-05-17 | 2006-12-07 | GM Global Technology Operations, Inc., Detroit | Control strategy of relative humidity profile for high current density stacking operation |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6656620B2 (en) * | 2000-01-31 | 2003-12-02 | Honda Giken Kogyo Kabushiki Kaisha | Humidification system for a fuel cell |
| US6884534B2 (en) * | 2001-05-03 | 2005-04-26 | General Motors Corporation | Electronic by-pass control of gas around the humidifier to the fuel cell stack |
| DE102004005446A1 (en) * | 2004-02-04 | 2005-08-25 | Robert Bosch Gmbh | Fuel-operated device for converting energy, in particular a fuel cell device |
| US20060263652A1 (en) * | 2005-05-17 | 2006-11-23 | Logan Victor W | Fuel cell system relative humidity control |
-
2007
- 2007-04-03 DE DE102007015955.4A patent/DE102007015955B4/en not_active Expired - Fee Related
-
2008
- 2008-03-27 WO PCT/EP2008/002401 patent/WO2008119495A1/en not_active Ceased
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000164231A (en) * | 1998-11-26 | 2000-06-16 | Toshiba Corp | Polymer electrolyte fuel cell system |
| US20010046616A1 (en) * | 2000-03-08 | 2001-11-29 | Mossman Alexander Douglas | Membrane exchange humidifier |
| US20060101994A1 (en) * | 2002-07-18 | 2006-05-18 | Daimlerchrysler Ag | Device and method for humidifying a gas flow |
| DE10246168A1 (en) * | 2002-10-02 | 2004-04-15 | Daimlerchrysler Ag | Fuel cell has pumped feedback loop to control the water content based on input and output moisture sensors |
| DE102006022864A1 (en) * | 2005-05-17 | 2006-12-07 | GM Global Technology Operations, Inc., Detroit | Control strategy of relative humidity profile for high current density stacking operation |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113224351A (en) * | 2020-01-21 | 2021-08-06 | 上海氢晨新能源科技有限公司 | Fuel cell stack humidity control system and method |
| CN115939460A (en) * | 2021-10-01 | 2023-04-07 | 洁能氏公司 | System and method for controlling and monitoring fuel cell stack using cathode exhaust humidity |
| EP4207402A1 (en) * | 2021-10-01 | 2023-07-05 | Cummins, Inc. | Systems and methods for controlling and monitoring a fuel cell stack using cathode exhaust humidity |
Also Published As
| Publication number | Publication date |
|---|---|
| DE102007015955B4 (en) | 2014-01-30 |
| DE102007015955A1 (en) | 2008-10-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE60214385T2 (en) | FUEL CELL SYSTEM WITH HYDROGEN SENSOR | |
| DE112007001734B4 (en) | The fuel cell system | |
| DE102007046056B4 (en) | A fuel cell system having improved water transfer efficiency in a membrane humidifier by reducing a dry air intake temperature | |
| DE102009050938B4 (en) | A method of controlling airflow to a fuel cell stack | |
| DE102017103524B4 (en) | Method for anomaly detection in the pressure sensor and fuel cell system | |
| DE112008000987B4 (en) | The fuel cell system | |
| DE10230702A1 (en) | Control device for a fuel cell | |
| DE102013211913A1 (en) | Fuel cell system and method for operating a fuel cell system | |
| DE102006022863B4 (en) | Method for operating a fuel cell system | |
| DE102014100751A1 (en) | Countermeasures for airflow errors in a fuel cell system | |
| DE102010051220A1 (en) | Online estimation of RH of a cathode inlet and outlet from a stack average HFR | |
| DE102007026332B4 (en) | Fuel cell system and method for cathode transfer moisture control in a fuel cell system | |
| DE102017102354A1 (en) | A method of operating a fuel cell system and adjusting a relative humidity of a cathode operating gas during a heating phase | |
| DE112008001025T5 (en) | The fuel cell system | |
| DE102009050934B4 (en) | Method and system for remedial measures in the event of failure of a cathode by-pass valve in a fuel cell system | |
| DE102015215927A1 (en) | Fuel cell system and method for operating such | |
| DE102008006726B4 (en) | Fuel cell system for controlling hydrogen emissions during upflow transients and cathode pulsing | |
| DE102007015955B4 (en) | Apparatus for operating a fuel cell system | |
| EP1702842A1 (en) | Aircraft comprising a fuel cell | |
| DE102017214967A1 (en) | Method for determining a state of aging of a humidifier and fuel cell system | |
| DE102011014278A1 (en) | Diagnostic concept for valve controlled coolant bypass paths | |
| DE102020115663A1 (en) | Fuel cell system with a central air supply, regulation and supply system and a motor vehicle with such a fuel cell system | |
| DE102015216343A1 (en) | Anode-cathode supply | |
| DE102022135013A1 (en) | fuel cell system | |
| DE102007022203B4 (en) | METHOD OF CONTROLLING THE RELATIVE HUMIDITY OF THE CATHODE EXHAUST OF A FUEL CELL STACK |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 08734796 Country of ref document: EP Kind code of ref document: A1 |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 08734796 Country of ref document: EP Kind code of ref document: A1 |