Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M16/00—Structural combinations of different types of electrochemical generators
  • H01M16/003—Structural combinations of different types of electrochemical generators of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers
  • H01M16/006—Structural combinations of different types of electrochemical generators of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers of fuel cells with rechargeable batteries
• • 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
  • H01M8/04—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
  • H01M8/04753—Pressure; Flow 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
  • H01M8/04—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
  • H01M8/04955—Shut-off or shut-down of fuel cells
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2250/00—Fuel cells for particular applications; Specific features of fuel cell system
  • H01M2250/20—Fuel cells in motive systems, e.g. vehicle, ship, plane
• • 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
  • H01M8/04097—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with recycling of the reactants
• • 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
  • Y02E60/10—Energy storage using batteries
• • 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
• • 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
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02T90/40—Application of hydrogen technology to transportation, e.g. using fuel cells

Definitions

• the invention relates to a control method for a fuel cell system for supplying energy to a consumer, wherein the fuel cell system is designed to react a fuel with an oxidant, wherein the fuel cell system is switchable between a rest state and an operating state, and wherein the energy supply of the consumer at rest or for the most part completely done by an energy storage device.
• the invention also relates to a fuel cell system for carrying out the control method.
• Fuel cell systems are energy supply units which convert chemical energy into electrical energy via an electrochemical process.
• fuel cell systems include one or more fuel cells having an anode region and a cathode region separated by a membrane. Through the anode region of the fuel, is passed through the cathode region of the oxidant, the membrane allows a proton migration between the areas and thus allows the reaction of the reactants to generate the electrical energy.
• fuel cell systems in vehicles, estimates have shown that it is advantageous for achieving high energy efficiency, for example, to stop the electrochemical process during standby phases and to ensure the energy supply via an energy storage device.
• Such fuel cell systems with energy storage devices are also referred to as hybrid systems.
• document US 2007/0054165 A1 which is probably the closest prior art, describes a fuel cell system which can be switched over between an operating state in which the fuel cells produce energy for a drive train and a rest state in which the electrochemical process is deactivated is.
• the document states that in the idle state, operating conditions may occur which deteriorate a restart of the fuel cell, which may result, for example, in a delay in power generation or a reduced voltage.
• it is proposed to intermittently move the fuel cell system or fuel cells from the idle state to the normal operating state.
• the invention is based on the object to propose a control method for a fuel cell system or a correspondingly designed fuel cell system, which has an improved strategy for controlling the fuel cell system at rest.
• a control method for a fuel cell system is proposed, which is suitable and / or designed for a power supply of a consumer.
• the concept of the consumer is preferably to be seen generally, wherein the consumer may also include a consumer system, in particular a vehicle with auxiliary consumers, such as turbomachines, lighting, etc., and one or more main consumers, such as a drive motor.
• the fuel cell system is designed to react a fuel, preferably hydrogen, with an oxidant, preferably oxygen, in particular ambient air.
• the fuel cell system is switchable between a rest state and an operating state.
• the operating state is preferably selected when the load is switched to a main load, in particular when a vehicle as a consumer supplies the drive motor with energy.
• the idle state the energy supply of the consumer is largely or even completely taken over by an energy storage device.
• the power generation of the fuel cell system in the sleep state is smaller than the power generation in the running state.
• Fuel cell system in particular the fuel cell is impaired.
• it is proposed, in the idle state to actively move the oxidant and / or the fuel in the fuel cell system, in particular in the fuel cells.
• This surprisingly simple measure can lead to a multiplicity of advantages: On the one hand, it is possible to avoid over-spreading the operating voltages of the different fuel cells in the fuel cell system by homogenizing the operating conditions with respect to the reactant distribution. Another possible advantage is that the reactant distribution in the fuel cell system is adjusted to allow for good or even optimal conditions for restarting or transitioning from the quiescent state to the operating state. Furthermore, it is possible to control the internal humidification of the fuel cells, in particular of the membranes.
• the fuel cell system has a first turbomachine, which is preferably designed as a compressor device, which is arranged and / or designed for compressing and / or accelerating the oxidant.
• the first turbomachine is preferably operated electrically, wherein the movement of the oxidant in the idle state is implemented by driving the first turbomachine.
• the fuel cell system has a second turbomachine, which is designed and / or arranged for compressing and / or accelerating the fuel.
• the movement of the fuel in the idle state by driving the second turbomachine takes place.
• the second turbomachine is arranged in a recirculation branch of the anode gas supply, that is, in terms of flow, is connected in a feedback path between the anode output and the anode input.
• a continuous ventilation of the fuel and / or the oxidant in the idle state - optionally with different delivery rates or speeds of the turbomachinery - performed.
• the first and / or the second turbomachine in the idle state are operated only intermittently, pulsed and / or temporarily.
• the first and / or the second turbomachine with a power and / or Speed and / or delivery rate are operated, which is less than the power or speed in the operating condition.
• the reactant (s) is intentionally operated in order to compensate for the negative consequences of the quiescent state and at the same time not to burden the energy efficiency.
• the rest state it is preferably provided that no energy conversion from chemical to electrical energy takes place.
• a certain degree of energy conversion is unavoidable by the circulation, but it is preferably provided that the converted energy is not transmitted to the energy storage device and / or the consumer and / or that the power generated at rest less than 20%, preferably less than 10% and in particular less than 5% of the power, in particular the rated power or maximum line, in the operating state.
• control method is designed for a fuel cell system which is designed as a mobile energy supply, preferably in a vehicle for supplying the drive train with drive energy.
• the fuel cell system is switched to the idle state if one, any selection or all of the following conditions are met:
• A The battery system is ready and has no fault.
• B A fuel cell fault is not active, ie no fuel cell system malfunction.
• the state of charge of the power supply device is greater than a state of charge limit, that is, the energy storage device is filled above the state of charge limit.
• the power to an inverter, which converts the electric power of the fuel cell system in an alternating current to supply a main load is smaller than a first power value.
• the current main load current is less than a first current limit, that is to say that of the main load, e.g. the powertrain of a vehicle, the power taken off is below a power limit.
• the battery temperature is lower than a first temperature limit.
• the coolant temperature is greater than a second temperature limit, that is, during the warm-up phase of the fuel cell system, this is not switched to the idle state, in order to achieve a sufficient operating temperature, for example, greater than 80 ° C.
• the non-idle time is greater than a time limit, that is, the idle state is activated after a predefined wait interval.
• J The speed of the first turbomachine is less than a speed limit.
• K The speed of the vehicle is less than a given speed value.
• the fuel cell system comprises a fuel cell device with at least one fuel cell, preferably more than 100 fuel cells, which are arranged in particular in stacks on. Furthermore, the fuel cell system comprises an energy storage device, which is designed for example as a rechargeable battery, accumulator or capacity. Preferably, the energy storage device is designed as a high voltage unit with a working voltage greater than 80 V, preferably greater than 100 V.
• a control device is provided, which can optionally be designed as a separate control device or as an integral part of a higher-level control device.
• the control device is designed in terms of programming and / or circuitry for controlling the fuel cell system according to the control method just described or according to one of the preceding claims.
• the fuel cell system is preferably designed as a mobile fuel cell system, in particular for use in a vehicle for supplying the drive energy.
• Figure 1 is a schematic block diagram of a fuel cell system as an embodiment of the invention
• FIG. 2 shows the fuel cell system in FIG. 1 with further details in a similar representation
• FIG. 3 is a schematic flow diagram illustrating a control method for controlling the fuel cell system according to FIGS. 1 and 2;
• FIG. 4 is a schematic flowchart for a detailed explanation of step A 1 in FIG. 3;
• FIG. 5 shows a schematic flow diagram for the detailed explanation of step A 7 in FIG. 3.
• FIG. 1 shows a schematic representation of a fuel cell system which can be used, for example, for use in a vehicle for supplying energy to the drive train.
• the fuel cell system includes a
• Fuel cell stack 1 with a plurality of fuel cells, each fuel cell of the fuel cell stack 1 having an anode region Ia and a cathode region Ib.
• the fuel cell system shows a hydrogen supply 2, which is formed for example as a hydrogen tank or a reformer and which supplies the anode regions Ia of the fuel cell stack 1 with hydrogen.
• An oxidant supply 3 is designed to supply the cathode regions 1 b of the stack 1 with an oxidant, in particular ambient air.
• the fuel cell system shows a cooling water supply 4.
• a sensor unit 5 monitors the temperature of the cooling water.
• the power outputs of the fuel cell stack 1 are connected on the one hand to a DC / DC converter 6 and in parallel to an inverter 9.
• the DC / DC converter 6 converts the applied voltage of the fuel cell stack 1 and supplies an energy storage device in the form of a high voltage battery 7.
• the DC / DC converter 6 and the high voltage battery 7 have a second cooling 8.
• the electrical power of the fuel cell stack 1 is converted into alternating voltage or current, with which a drive motor 10 and auxiliary components - in summary designated by the reference numeral 11 - are supplied.
• the high-voltage battery 7 is a second and / or alternative energy source for supplying the drive motor 10 and / or the auxiliary components 11
• Fuel cell system is a control device 12 which receives state signals of the components of the fuel cell system as input variables and outputs control signals.
• control device 12 receives state signals of the components of the fuel cell system as input variables and outputs control signals.
• material flows ie in particular gas and liquid flows with solid lines Ll
• electric power currents with coarse broken lines L2 and signal streams are shown with dotted lines L3.
• FIG. 2 shows a more detailed illustration of the fuel cell system of FIG. 1, in particular of the auxiliary components 11.
• a first auxiliary component in the form of a fan IIa is arranged in a recirculation branch, which returns unused fuel from the anode outlet to the anode inlet.
• the fan IIa is driven by means of a motor IIb.
• auxiliary component is the coolant pump 11c, which is driven by a motor Hd.
• the air supply 3 has a compressor He, which is driven by an electric motor Hf.
• step A1 shows a schematic flowchart of a method for controlling the fuel cell system in the preceding figures as an embodiment of the invention. After the start of the method, it is checked in step A1 whether the conditions explained in connection with FIG. 4, in particular completely, are met. In the event that these conditions are not met, the entry into a resting state of the fuel cell system is prevented according to step A2.
• step A3 via the control device 12 ( Figure 2) at least the Compressor motor Hf set in a stop mode, that is, the rotational speed is reduced to zero revolution per minute.
• the DC / DC converter 6 keeps the fuel cell stack 1 within a predetermined voltage range.
• the lower limit of the voltage range is given by the limit, which is used by the auxiliary equipment of the vehicle and the fuel cell system, which are still in operation.
• the DC / DC converter 6 is also used to set in the stop mode the voltage between the fuel cell stack 1 and the high voltage battery 7 so that the current of the fuel cell stack 1 zero amps or very close to zero amps, for example, less than 10 amps is.
• step A5 it is judged whether a predetermined time interval has passed. If this interval has passed, an intermittent operation is started, whereby the compressor motor Hf is activated.
• the delivery rate of the compressor motor Hf is increased to a low level, in particular to a level which is below the level in normal operation, and held according to step A6 for a predetermined time.
• the power supply of the compressor motor 11 and the other auxiliary components 11 takes place during the idle state via the high-voltage battery 7. During the entire idle state of the fan motor Hb remains activated, but also at a reduced speed.
• step A7 it is checked if abort conditions for canceling the sleep state exist.
• FIG. 4 is a flow chart, in more detail, associated with a logical AND / AND Conditions shows which must all be met for the fuel cell system to go to sleep (step BlI). If only one of the conditions is not met, entry into the idle state according to step B12 is prevented.
• step Bl it is checked
• Fuel cell mode operates, that is, in which the only power supply is the fuel cell stack 1 and the traction battery 7 does not join the power supply, and
• step B2 it is examined
• step B3 it is examined
• step B4 it is examined
• step B5 it is examined
• step B6 it is examined
• step B7 it is examined
• step B8 it is examined
• step B9 it is examined
• step BIO In step BIO must be examined
• FIG. 5 shows in the form of a flowchart the steps which are necessary to terminate the idle state according to step A7 (FIG. 3).
• the steps shown are linked together via a logical OR / OR, so that each of the steps can trigger a transition from the idle state to the operating state according to step C7. Otherwise, the fuel cell system remains at rest in step C8.
• step C 1 it is examined
• step C2 it is examined
• step C3 it is examined - Whether the recorded electric power of the drive motor is greater than a predetermined value.
• step C4 it is examined
• step C5 it is examined
• step C6 it is checked
• the invention discloses, in possible embodiments, a control method which prevents an inadmissible spreading of the operating voltages of the individual fuel cells in damage-causing areas during idle operation and improves the restartability of the fuel cell system. This is achieved in that the supply of reactant gases and / or adequate humidification of the fuel cells is ensured in the idle mode or during idle operation.
• a hydrogen accumulation is avoided by a forced circulation of the oxidant, preferably by means of the compressor.
• it is possible to decompose condensate by the drying effect of the oxidant by or intermittent operation of the compressor.

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

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• 2008
  • 2008-03-20 DE DE102008015344A patent/DE102008015344A1/de not_active Withdrawn
• 2009
  • 2009-03-13 JP JP2011500084A patent/JP2011517015A/ja active Pending
  • 2009-03-13 WO PCT/EP2009/001837 patent/WO2009115243A1/de not_active Ceased
  • 2009-03-13 US US12/933,664 patent/US20110053015A1/en not_active Abandoned

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