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
  • H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
  • H01M8/04014—Heat exchange using gaseous fluids; Heat exchange by combustion of 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
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
  • H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
• • 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
  • H01M8/04223—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells
  • H01M8/04225—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells during start-up
• • 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
  • H01M8/043—Processes for controlling fuel cells or fuel cell systems applied during specific periods
  • H01M8/04302—Processes for controlling fuel cells or fuel cell systems applied during specific periods applied during start-up
• • 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
• • 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
  • H01M8/2457—Grouping of fuel cells, e.g. stacking of fuel cells with both reactants being gaseous or vaporised
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2300/00—Electrolytes
  • H01M2300/0017—Non-aqueous electrolytes
  • H01M2300/0065—Solid electrolytes
  • H01M2300/0082—Organic polymers
• • 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
  • H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
  • H01M8/04014—Heat exchange using gaseous fluids; Heat exchange by combustion of reactants
  • H01M8/04022—Heating by combustion
• • 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 a fuel cell battery with improved cold start performance and a method for cold starting a fuel cell battery in which the heat of reaction of the combustion of the process gases is used to heat the fuel cell during the cold start.
• EP 0 924 163 A2 discloses a method for steam reforming a hydrocarbon or a hydrocarbon derivative, as well as a reforming system that can be operated with it, and a fuel cell operating method in which the heat of an external catalytic burner device is used to warm up the system during a cold start.
• a fuel cell battery has one electrolyte per fuel cell unit, such as an ion exchange membrane in the PEM fuel cell, which contains a sulfonated chemical compound as the main component.
• This group of chemical compounds binds water in the membrane to ensure adequate proton conductivity.
• the membrane resistance suddenly increases by 2-3 powers of ten due to the freezing of the stored water.
• the PAFC Phosphoric Acid Fuel Cell
• PAFC Phosphoric Acid Fuel Cell
• either the battery, even without use, can be operated at minimal load so that the temperature does not drop below the freezing point drops, or a thermal sensor can be installed so that the moment the temperature drops so far that the electrolyte resistance threatens to rise suddenly, the battery starts up and heats up due to operation.
• a disadvantage of short-circuit operation is that an extremely high internal resistance of the electrolyte must be overcome at temperatures below freezing until the cell is started to run and can heat up as a result.
• the object of the present invention is to provide a fuel cell battery with improved cold start performance, which can be started at low temperatures without a drastically increased consumption of process gas. It is also an object of the invention to provide a method by which a fuel cell battery can be started cold.
• the invention relates to a fuel cell battery with at least one fuel cell unit, which comprises a reaction chamber on each side of the centrally arranged electrolyte electrode unit and process gas channels, at least one additional line being provided in at least one reaction chamber and / or to the bipolar plates which metered reaction and / or process gas when starting and / or can be generated there in situ.
• the areas covered with catalyst are thus used as a catalytic burner during a cold start.
• the invention also relates to a method for cold starting a fuel cell battery, in which the waste heat from the combustion of the primary and / or secondary fuel is used to heat the fuel cell stack, reaction and / or process gas from the counter electrode being metered into at least one reaction chamber and / or is generated there in situ, so that on cold start all surfaces which are covered with catalyst and which both reaction gases encounter are used as catalytic burners.
• the additional line establishes a connection between the process gas channel for oxidant and the anode and / or the process gas channel for fuel and the cathode.
• This connection can be equipped with a metering valve, automatic control of the metering valve via a control unit, which is used as a control variable, for example: the temperature in the anode and / or cathode chamber, being advantageous.
• the additional line establishes an electrical contact between the two electrodes and / or the adjacent bipolar plates and an external voltage source, so that oxygen and / or in is targeted in the anode chamber by electrolysis, possibly with periodic polarity reversal of the cell hydrogen can be generated in situ in the cathode chamber.
• the amount of reaction gas generated can be adjusted directly via the amount of electricity added.
• the reaction gas is added in an amount. is metered, which ensures that the temperature at the catalyst does not exceed 100 ° C.
• additional parts such as e.g. Gas inlets and outlets, bipolar plate and / or gas distribution and / or collection channels are coated with catalyst, so that oxidation and / or reduction takes place at these points as soon as reaction gas is metered in, with the development of heat.
• a fuel cell battery comprises at least one stack with a fuel cell unit, which is referred to as a stack, the corresponding process gas supply and disposal channels (axial process gas channel), a cooling system and associated end plates.
• a reformer can be integrated in the fuel cell system or operated externally.
• the process gas channel is e.g. directly connected to an oxygen or fuel tank, with a compressor and / or with a hydrogen and / or reformer gas (intermediate) storage, or also, preferably via a reformer, with a primary fuel line (natural gas line).
• reformer or H 2 gas can be temporarily stored, which is metered into the cathode compartment during cold start.
• the “at least one additional line into a reaction chamber ⁇ (term from the main claim) is preferably connected directly to a process gas channel.
• a PEM fuel cell battery is preferably used, but the application of the invention to other fuel lines, in particular the PAFC, is obvious.
• a fuel cell unit comprises an electrolyte arranged centrally, ie in the middle, which has an electrode on both sides, whereby in the case of PEM it is coated with an electrocatalyst like a sandwich.
• the electrode works like a catalytic burner, which permits controlled combustion of the reaction gas mixture and heats itself and its surroundings.
• a catalytic burner is characterized in that a strongly exothermic reaction takes place there in a controlled manner with the aid of a catalyst, so that the exothermic energy that is released can be used as heat. This does not result in an open flame even when burned, but the catalytic burner only produces heat.
• the gas of the pure reactant is referred to as the reaction gas, whereas the gas / liquid mixture which is introduced into the reaction chamber is referred to as the process gas.
• the process gas comprises several components such as e.g. Steam, inert gas, etc. in addition to the reaction gas and can also include primary fuel (before or after reforming).
• the primary fuel is gasoline, methanol, methane, etc., ie fuels from which a secondary fuel, such as a hydrogen-containing gas mixture or hydrogen, is produced in a reformer.
• Hydrogen can also be primary gas, for example in the case of H 2 storage.
• the reaction chamber is either the cathode or the anode chamber.
• the reaction chamber basically forms the space between the electrode and the bipolar plates.
• At least one process gas supply duct and one process gas discharge duct lead into this chamber, both of which are generally axially mounted in the fuel cell stack and are therefore also called axial process gas ducts.
• From gas inlet to gas outlet one Reaction chambers guide gas distribution and collection channels, which are often integrated in the bipolar plates. All areas of the reaction chamber can be covered with catalyst, so that the areas covered with catalyst can be used as catalytic burners not only in the immediate vicinity of the electrolyte at the electrode, but anywhere in the reaction chamber.
• the stack may flow through heated gases, e.g. from the reformer, or by simply decoupling the reformer heat via a heating circuit, so that not only the combustion and / or oxidation in the reaction chamber itself heats the stack, but also heat is supplied from the outside.
• the use in the mobile and decentralized area is in the foreground, but the use in the stationary area is also obvious.
• the invention for the first time discloses a method for cold starting a fuel cell battery that works simply, inexpensively and effectively.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Fuel Cell (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=7900275

Family Applications (1)

Country Status (6)

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• 2000
  • 2000-03-09 WO PCT/DE2000/000742 patent/WO2000054356A1/de not_active Application Discontinuation
  • 2000-03-09 CA CA002367134A patent/CA2367134A1/en not_active Abandoned
  • 2000-03-09 CN CN00804733A patent/CN1343379A/zh active Pending
  • 2000-03-09 EP EP00925042A patent/EP1166381A1/de not_active Withdrawn
  • 2000-03-09 JP JP2000604480A patent/JP2002539586A/ja not_active Withdrawn
• 2001
  • 2001-09-10 US US09/950,426 patent/US20020058165A1/en not_active Abandoned

Non-Patent Citations (1)

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