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
  • H01M8/02—Details
  • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
  • H01M8/0267—Collectors; Separators, e.g. bipolar separators; Interconnectors having heating or cooling means, e.g. heaters or coolant flow channels
• • 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
  • H01M8/04007—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
  • H01M8/04029—Heat exchange using liquids
• • 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
  • H01M8/04067—Heat exchange or temperature measuring elements, thermal insulation, e.g. heat pipes, heat pumps, fins
  • H01M8/04074—Heat exchange unit structures specially adapted for 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
  • H01M8/04082—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
  • H01M8/04111—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants using a compressor turbine assembly
• • 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
  • H01M8/04291—Arrangements for managing water in solid electrolyte fuel cell systems
• • 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
  • H01M8/10—Fuel cells with solid electrolytes
  • H01M2008/1095—Fuel cells with polymeric electrolytes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2220/00—Batteries for particular applications
  • H01M2220/20—Batteries 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
  • 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
• • 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 fuel cell stack with a large number of individual cells stacked to form a stack, according to the type defined in more detail in the preamble of claim 1.
• various peripheral components are necessary for the operation of fuel cell stacks.
• these include components for processing the supply air used as an oxygen supplier and can include intercoolers and humidifiers.
• the applicant's DE 10 2007 038 880 A1 describes a fuel cell arrangement with a fuel cell stack, a charge air cooler and a humidifier, which are combined to form a structural unit.
• the object of the present invention is to further optimize a fuel cell stack in order to be able to implement a fuel cell system equipped with it in a compact and cost-effective manner.
• the fuel cell stack according to the invention it is comparable to the fuel cell stack in the last-mentioned prior art that it comprises a large number of stacked individual cells, and that a humidifier is integrated into the stack and is arranged at one end of the individual cells. In principle, two humidifiers at both ends of the individual cells of the stack would also be conceivable.
• an intercooler is arranged on the side of the at least one humidifier facing away from the individual cells.
• Flow plates which are present for distributing fluids in the at least three sections of the stack, have the same external geometry in the fuel cell stack according to the invention. The flow plates used are therefore designed identically with regard to their external geometry, so that they can be stacked up to form an overall stack without any problems.
• the concepts for sealing between the individual flow plates and for connecting the individual cells and the sections of the entire stack can be transferred from the previous electrochemical individual cells to the other sections of the humidifier and the charge air cooler.
• This design ensures that all incoming airflow is evenly cooled and humidified before entering the individual cells.
• this structure could also be transferred to the hydrogen stream, which would be preheated according to the relax and then moistened, with a humidification of the terms in general sufficiently humidify the individual cells realized in PEM technology.
• connection openings of the flow plates of the at least three sections have the same geometry, with distributor plates for the media being attached between the sections.
• the connection openings which in a stack typically form a continuous volume for distributing the media to the flow fields of the individual cells through which flow occurs in parallel, are therefore preferably identical in all flow plates.
• each flow plate includes an opening corresponding to the anode-side inflow opening and outflow opening, an opening corresponding to the cathode-side inflow and outflow opening and an opening corresponding to the cooling medium inflow and outflow opening analogous to the flow plates of the individual electrochemical cells.
• Connection openings ensure channels of the sections to one another or, for example, also ensure corresponding connection openings for the cooling medium if this is merely passed through the area of the intercooler and/or the humidifier.
• Another very favorable embodiment of the fuel cell stack according to the invention provides that in the section used as a charge air cooler, thermally conductive, temperature-resistant foils are arranged between two flow plates, through which the inflowing gas and the outflowing gas flow alternately.
• the individual flow plates can be designed for the section of the heat exchanger as well as for the section of the humidifier in such a way that flow channels for one of the gas flows, for example the supplied gas, are formed on their one surface and flow channels for the outflowing gas are formed on their opposite side .
• the plates are then arranged mutually twisted, so that between the plates in the case of be positioned for water vapor permeable membranes in the case of the section used as a humidifier. This allows for a simpler and more efficient construction.
• the structure can be implemented on one or both sides of the individual cells at the respective ends of the stack. This can also contribute to the fact that the thermal management of the individual cells in the end area of the stack is improved accordingly, because they are now adjacent to the humidifiers and do not cool down more due to their arrangement adjacent to the end plates of the stack, which is the case with structures according to the prior art is sometimes difficult. This further simplifies the structure of the end plates, since electrical heating of the same can be dispensed with in a structure of the stack according to the invention, at least if these are not arranged adjacent to the individual cells, but rather adjacent to the structure of charge air cooler and humidifier.
• a structure can also be implemented in the section of the fuel cell stack used as a charge air cooler which, comparable to the structures of the flow fields in the electrochemical cells, has these in such a way that on one Side have a flow field for one of the media and on their other side for a cooling medium. If two such panels are connected to one another back to back, a structure is created in which, for example, the supply air can flow on one side and the exhaust air can flow on the other side of the sandwich, with a cooling medium flowing in between.
• the flow is such that the cooling medium first flows through the individual cells and then through a section of the fuel cell stack constructed in this way, which is used as a charge air cooler.
• This can also be done in a similar way in the area of the humidifier, so that here too the structures can be implemented in accordance with those of the electrochemical individual cells, but without the gas diffusion layers and catalysts.
• the same membranes could even be used here, with a further advantage being able to be achieved here through more cost-effective membranes.
• the cooling medium could be used to cool the inflowing gases during humidification.
• fuel cell stacks of this type can preferably be designed using PEM technology and are used in particular, but not exclusively, in vehicles.
• vehicles for example in passenger cars or commercial vehicles, such as in particular trucks, they serve to provide electrical drive power from entrained hydrogen and air sucked in from the environment as an oxygen supplier.
• FIG. 1 shows a schematic representation of a first possible embodiment of a fuel cell stack according to the invention
• FIG. 2 shows an alternative possible configuration of a fuel cell stack according to the invention in a representation analogous to that in FIG. 1;
• FIG. 3 top view of a flow plate such as can be used, for example, in the area of the section used as an intercooler or humidifier;
• FIG. 4 shows a schematic sectional illustration through a section of flow plates in the section used as charge air cooler and/or humidifier with flow plates according to FIG. 3;
• FIG. 5 shows a flow plate analogous to that in FIG. 3 in an alternative embodiment
• FIG. 6 shows a structure analogous to that in FIG. 4 with flow plates according to the structure shown in FIG.
• a possible structure of a fuel cell stack 1 is shown in an embodiment according to the invention.
• An electrochemical section 3 which is provided with a plurality of individual cells for providing the electrical power.
• This section 3 consists of stacked individual cells using PEM technology and essentially corresponds to a conventional fuel cell stack or fuel cell stack.
• a humidifier section 4 followed by a heat exchanger section 5.
• the humidifier section 4 is used to humidify the supply air flowing into the electrochemical section 3 in which moisture from the exhaust air of the electrochemical section 3 is used for humidification.
• the structure is a plate humidifier with membranes 22 permeable to water vapor, which are shown later.
• the heat exchanger section 5 serves as an intercooler in order to correspondingly cool the incoming air, which is typically hot and dry after its compression, for example from temperatures of 200 to 250 °C, which are usual after compression, to a temperature level of approx. 100 °C, for example 80 to 120 °C.
• the flow path is now shown by the arrows.
• the supply air flows on one side of the heat exchanger section 5 at the point designated by 6 and flows through it. It is then deflected by a distribution plate, not shown here, after it has flowed through the flow plates of the heat exchanger section 5 in parallel. Now it flows in series through the humidifier section 4, within which it also flows parallel to one another through the individual flow plates.
• the supply air flow cooled and humidified in this way then arrives in the area of a further distribution plate and at the point designated here as 7 in the electrochemical section 3 and flows through its individual cells in parallel.
• the moist exhaust air from the electrochemical section 3 then returns to the humidifier section 4 at the point designated 8 and releases the moisture contained in it to the supply air.
• the exhaust air then flows into the heat exchanger section 5 and absorbs heat from the supply air flow before it flows out of the fuel cell stack 1 again at point 9 .
• End of the electrochemical section 3 provided and integrated between the end plates 2 of the structure.
• the structure could also be designed as indicated in FIG. In this case, the structure is correspondingly integrated at both ends of the electrochemical section 3, without the flow being explicitly drawn again here, which makes additional connecting lines necessary.
• the two end plates 2 are arranged in a conventional manner immediately adjacent to the electrochemical section 3, while the humidifier sections 4 and the heat exchanger sections 5 are provided as charge air coolers outside the end plates 2 on both sides.
• Both structures according to FIGS. 1 and 2 can be combined with one another as desired, so the structure could also be provided on both sides of the electrochemical section 3 inside the end plates 2, or only on one side, analogous to the representation in FIG. 1 but outside of the end plate 2, as indicated in FIG.
• the individual sections 3, 4, 5 now include flow plates 10, 10'.
• These flow plates 10, 10' which are often designed as bipolar plates, are fundamentally known to the person skilled in the art from the field of the electrochemical section and here of the individual cells.
• This type of flow plates can now also be used largely identically in the other sections 4, 5, whereby it is also possible to switch to more cost-effective materials and manufacturing processes for the flow plates, but without changing the geometry of the same, and this relates in particular to the outer one Geometry and the geometry of port openings to change.
• the entire structure can then be stacked in the manner known from the electrochemical section 3 and sealed off easily, reliably and in the manner known per se via seals between the individual flow plates 10, 10'.
• FIG. 10 A plan view of a possible structure of two such flow plates 10, 10' can be seen in FIG. They include three port openings on each side. These connection openings are denoted by reference numerals 11, 12 and 13 on one side and 14, 15, 16 on the other side.
• connection openings are denoted by reference numerals 11, 12 and 13 on one side and 14, 15, 16 on the other side.
• the connections 11 and 16 on the side facing the viewer should now be connected to one another via a flow field 17 17 and the respective connection openings 11 and 16, the so-called manifolds 18, are indicated accordingly.
• a flow channel denoted by 20 is thus formed.
• the two cooling water connections 12, 15 are then connected to one another on the opposite side of the flow plate 10, which is not visible here.
• a coolant channel designated 19 is thus formed.
• the channel for the cooling medium designated 19 here
• the channel designated 20 for one medium on the opposite side on the surface of the other flow plate 10' a channel for the other medium.
• a membrane or foil 22 is now arranged between the channels 20, 21 for one and the other medium, and this can be seen in the illustration in FIG. In the area of the humidifier section 4, this membrane or film 22 can be a membrane permeable to water vapor, which thus enables an exchange of water vapor between the media flowing in the channel 20 and 21.
• the dry supply air and the moist exhaust air are conducted in the respective channels 20, 21 in order to be able to humidify the dry intake air in the humidifier section 4 by the moist exhaust air.
• such membranes are typically unsuitable because they do not withstand the relatively high temperatures of the compressed, dry and hot supply air, or do not do so in the long term.
• metal foils, graphite foils as are temperature-resistant and enable good heat exchange between the hot supply air and the significantly cooler exhaust air.
• temperature control can also be achieved in both cases via the cooling medium flowing in the cooling channel 19, analogously to the structure of the individual cells in the electrochemical region 3.
• FIGS. 3 and 4 As an alternative to the structure described in FIGS. 3 and 4, however, a variant is also conceivable which is of correspondingly simpler design and dispenses with the additional flow of cooling medium and the cooling channel 19 required for this. Only a single flow plate 10 is then necessary for this, as indicated accordingly in the representation of FIG.
• This flow plate 10 corresponds in its geometry to the previously shown flow plate 10. On the rear side, which cannot be seen here, it is not the openings 12 and 15 that are connected to one another, but the openings 13 and 14, so that a structure is created which, on the one hand, one side of the flow plate 10 previously described and on the other side having one side of the flow plate 10' previously described.
• connection openings 11 to 16 can also be used here in order to keep the geometry of the stack the same across all sections 3, 4, 5, particularly in the case of an integrated arrangement between the end plates.
• the openings 12 and 15 typically provided for the cooling water can then, for example, not be used or can also be combined with other openings.
• the openings 11 and 12 can be used as a common inflow opening for one medium and accordingly the openings 15 and 16 as common outflow openings. This can, for example, by connecting the individual openings in the head and Manifolds 18 are connected to the flow field 17.

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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 (2)

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• 2020
  • 2020-08-27 DE DE102020005246.0A patent/DE102020005246A1/de active Pending
• 2021
  • 2021-07-29 CN CN202180051291.5A patent/CN115968510A/zh active Pending
  • 2021-07-29 US US18/042,805 patent/US20230238553A1/en active Pending
  • 2021-07-29 JP JP2023512074A patent/JP2023545348A/ja active Pending
  • 2021-07-29 EP EP21759252.6A patent/EP4205205A1/de active Pending
  • 2021-07-29 WO PCT/EP2021/071261 patent/WO2022042991A1/de unknown
  • 2021-07-29 KR KR1020237009731A patent/KR20230056723A/ko unknown

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