Proton exchange membrane fuel cell assembly or electrolyzer
By restricting coolant flow in the first and last cells of the fuel cell assembly, the assembly achieves uniform temperature distribution, addressing the issue of premature aging and enhancing the lifespan of the fuel cell stack.
Patent Information
- Application Number
- FR2024007557
- Authority / Receiving Office
- FR · FR
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2024-07-11
- Publication Date
- 2026-01-16
- Estimated Expiration
- 2034-07-11
AI Technical Summary
State-of-the-art fuel cells face challenges in maintaining uniform temperature profiles across all cells in a stack due to varying heat dissipation rates at the end cells, leading to premature aging and reduced lifespan.
A fuel cell assembly design with restricted coolant flow rates in the first and last cells through the use of restricted coolant inlet and outlet manifold ports, reducing coolant flow by 20% to 50%, ensuring uniform temperature distribution across the stack.
The solution maintains uniform temperature profiles across the entire stack, preventing premature aging and extending the lifespan of the fuel cell assembly.
Smart Images
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Abstract
Description
Title of the invention: Proton exchange membrane fuel cell assembly or electrolyzer
[0001] The present invention relates to a proton exchange membrane fuel cell assembly or electrolyzer, a fuel cell or electrolyzer comprising such an assembly.
[0002] The invention relates more particularly to an assembly comprising a stack of a plurality of proton exchange membrane fuel cell cells in which the cells each comprise an anodic plate and a cathodic plate sandwiching a Membrane Electrode Assembly (MEA).
[0003] Fuel cell cells (anode side and cathode side) generate heat (the chemical reactions within the cell are exothermic) and must be cooled by a cooling circuit.
[0004] In the case of a cell composed of two plates sandwiching a Membrane Electrode Assembly, each plate (anodic or cathodic) includes one side dedicated to the circulation of reactive gases (air or hydrogen opposite the Membrane Electrode Assembly) and one side (facing outwards from the cell) dedicated to the circulation of the cooling fluid (often a liquid).
[0005] Each cell in the stack must be cooled in the same way to ensure a uniform performance degradation over time. Indeed, an isolated cell, aging prematurely, can compromise the lifespan of the entire stack. Managing the two cells located at the ends of the stack can be challenging, as there is no heat input from one side of these cells. Thus, for an identical inlet coolant temperature, and given that the heat to be dissipated is less at these two cells located at the ends of the stack than at the other cells, this means that the cell is cooler.
[0006] With state-of-the-art fuel cells, it is therefore impossible to guarantee that all cells have substantially the same difference between the temperature of the coolant entering the cell and the temperature of the coolant leaving the cell.
[0007] The present invention aims to effectively overcome these drawbacks by proposing an assembly comprising a stack of a plurality of proton exchange membrane fuel cell or electrolyzer cells, the stack being sandwiched between a first end plate and a second end plate, the plurality of cells comprising a first cell with a first end of the stack and a final cell at a second end of the stack, each cell comprising two monopolar plates, respectively an anodic plate and a cathodic plate, each monopolar plate comprising a reactive face and a cooling face opposite to each other, the reactive face being intended to face an Electrode Membrane Assembly, the cooling face of each monopolar plate being intended to form, together with the cooling face of another of the monopolar plates or with the first end plate or with the second end plate, a cooling circuit for the circulation of a cooling fluid,each monopolar plate having a coolant inlet manifold port for the entry of the coolant into the cooling circuit and a coolant outlet manifold port for the discharge of the coolant having passed through the cooling circuit, the cooling circuit having a plurality of cooling ducts, a coolant distribution circuit fluidly connecting the coolant inlet manifold port to the cooling ducts and a coolant discharge circuit fluidly connecting the coolant outlet manifold port to the cooling ducts,The cooling fluid distribution circuit and / or the cooling fluid discharge circuit of the first and last cells each include a restriction configured to limit the flow rate of cooling fluid entering and / or exiting the cooling ducts, relative to the other cells in the stack.
[0008] The invention thus makes it possible to provide a fuel cell or electrolyzer assembly in which the first and / or last cell differs from the other cells with respect to the cooling circuit. Such a limitation of the cross-sectional area of the cooling fluid at the first and / or last cell reduces the flow rate of the cooling fluid entering or leaving the cooling circuit, particularly by 20% to 50%. This ensures a uniform temperature profile throughout the entire stack. Therefore, the lifespan of the fuel cell or electrolyzer is no longer reduced by the specific action of the first and / or last cell.
[0009] According to one embodiment, the first end plate is a distribution plate for the cooling fluid through the stack.
[0010] According to one embodiment, the second end plate is a sealing plate, in particular configured to allow the orifice to be fluidly re-looped reactive fluid inlet manifold with cooling fluid outlet manifold port.
[0011] According to one embodiment, the coolant inlet manifold orifice opens into the coolant distribution circuit via a distribution section, the distribution section being considered in a plane cutting a first gasket groove formed on the reactive face and surrounding the coolant inlet manifold orifice, the distribution section of the coolant distribution circuit of the first cell and / or the last cell being smaller than that of the coolant distribution circuits of the other cells.
[0012] According to one embodiment, the coolant outlet collector orifice opens into the coolant evacuation circuit, via an evacuation section, the evacuation section being considered in a plane cutting a second joint groove formed on the reactive face and surrounding the coolant outlet collector orifice, the evacuation section of the coolant evacuation circuit of the first cell and / or the last cell being smaller than that of the coolant evacuation circuits of the other cells.
[0013] According to one embodiment, the coolant inlet manifold port and / or the coolant outlet manifold port has a hole through the monopolar plate.
[0014] According to one embodiment, the restriction is configured to reduce the flow rate of the cooling fluid entering the cooling ducts and / or exiting the cooling ducts, by at least 20% to 50%, compared to the other cells in the stack.
[0015] According to one embodiment, the restriction is achieved by at least one plug inserted in the cooling fluid evacuation circuit or in the cooling fluid distribution circuit, of the first cell and / or the last cell, the plug being in particular made of elastomeric material.
[0016] Alternatively, each monopolar plate is produced by molding from a mold, the restriction being produced by molding by adding an insert into said mold.
[0017] According to one embodiment, the reactive face of each monopolar plate is intended to form, together with the reactive face of another monopolar plate, a reagent circuit for the circulation of a reactive fluid. Each monopolar plate has a reactive fluid inlet manifold for the entry of the reactive fluid into the reagent circuit and a reactive fluid outlet manifold for the discharge of the reactive fluid that has passed through the reagent circuit. The reagent circuit comprises a plurality of reagent conduits and a fluid distribution circuit. reactive fluid connecting the reactive fluid inlet manifold orifice to the reactive fluid lines and a reactive fluid evacuation circuit connecting the cooling fluid outlet manifold orifice to the reactive fluid lines.
[0018] According to one embodiment, the plurality of reagent channels is intended to face a diffusion layer of the Membrane Electrode Assembly, the plurality of cooling channels extending in particular over a surface substantially aligned with that in which the plurality of reagent channels extends.
[0019] According to one embodiment, the cooling fluid distribution circuit and the cooling fluid evacuation circuit are each arranged on a peripheral area of the monopolar plate, in particular around the surface in which the plurality of cooling ducts extend.
[0020] According to one embodiment, the first end plate is fixed or welded to one of the monopolar plates of the first cell and / or the second end plate is fixed or welded to one of the monopolar plates of the last cell.
[0021] The invention further relates to a fuel cell or an electrolyzer comprising an assembly as described above.
[0022] The invention may also relate to any device comprising any combination of the above or below characteristics.
[0023] The invention will be better understood upon reading the following description and examining the accompanying figures. These figures are given only by way of illustration and in no way limit the invention.
[0024] [Fig.1] Fig.1 is a schematic representation of an assembly according to the invention;
[0025] [Fig.2] [Fig.2] is a schematic, partial, cross-sectional representation of the entire [Fig.1]; and
[0026] [Fig.3] [Fig.3] is a schematic, partial and elevational representation of the whole of [Fig.1].
[0027] With reference to [Fig.1], an assembly 1 is shown comprising a stack of a plurality of proton exchange membrane fuel cell or electrolyzer cells 30.
[0028] The stack is sandwiched between a first end plate 11 and a second end plate 21.
[0029] The plurality of cells 30 comprises a first cell 301 at a first end of the stack and a last cell 302 at a second end of the stack.
[0030] Each cell 30 comprises two monopolar plates 10, 20, respectively an anodic plate 10 and a cathodic plate 20.
[0031] Each monopolar plate 10, 20 comprises a reactive face 22 and a cooling face 23 opposed to each other, the reactive face 22 being intended to face a Membrane Electrode Assembly 16.
[0032] The cooling face 23 of each monopolar plate 10, 20 is intended to form, together with the cooling face 23 of another of the monopolar plates 10, 20 or with the first end plate 11 or with the second end plate 21, a cooling circuit 15 for the circulation of a cooling fluid 40.
[0033] Each monopolar plate 10, 20 has an inlet collector port 5 for the coolant to enter the coolant circuit 15.
[0034] Each monopolar plate 10, 20 further includes a collector outlet 8 for the cooling fluid for the evacuation of the cooling fluid having passed through the cooling circuit 15.
[0035] The cooling circuit 15 comprises a plurality of cooling conduits 14.
[0036] The cooling circuit 15 further includes a distribution circuit 13 for the cooling fluid fluid connecting the inlet manifold port 5 of the cooling fluid to the cooling conduits 14.
[0037] The cooling circuit 15 further includes a cooling fluid evacuation circuit fluidly connecting the outlet manifold 8 of the cooling fluid to the cooling conduits 14.
[0038] The cooling fluid distribution circuit 13 and / or the cooling fluid drainage circuit 26 of the first 301 and last 302 cells each have a restriction configured to limit the flow of cooling fluid entering the cooling ducts 14 and / or exiting the cooling ducts 14, relative to the other cells 30 of the stack.
[0039] The inlet manifold port 5 of the cooling fluid opens into the distribution circuit 13 of the cooling fluid via a distribution section.
[0040] The distribution section is considered in a plane cutting a first joint groove 9 formed on the reactive face 22 and surrounding the inlet manifold orifice 5 of the cooling fluid.
[0041] The distribution section of the cooling fluid distribution circuit 13 of the first cell 301 and / or the last cell 302 is smaller than that of the cooling fluid distribution circuits 13 of the other cells 30.
[0042] The coolant outlet collector port 8 opens into the coolant drain circuit, via a drain section.
[0043] The evacuation section is considered in a plane cutting a second joint groove formed on the reactive face 22 and surrounding the outlet collector orifice 8 of the cooling fluid.
[0044] The evacuation section of the cooling fluid evacuation circuit of the first cell 301 and / or the last cell 302 is smaller than that of the cooling fluid evacuation circuits of the other cells 30.
[0045] The inlet collector port 5 of the cooling fluid has a hole through the monopolar plate 10, 20.
[0046] The coolant outlet collector orifice 8 has a hole through the monopolar plate 10, 20.
[0047] The restriction is configured to reduce the flow rate of the cooling fluid entering the cooling ducts 14 and / or exiting the cooling ducts 14, by at least 20% to 50%, compared to the other cells 30 of the stack.
[0048] The restriction is achieved by at least one plug inserted in the cooling fluid drain circuit or in the cooling fluid distribution circuit 13, of the first cell 301 and / or the last cell 302, the plug being in particular made of elastomeric material.
[0049] Alternatively, each monopolar plate 10, 20 is produced by molding from a mold, the restriction being produced by molding by adding an insert into said mold.
[0050] The reactive face 22 of each monopolar plate 10, 20 is intended to form, together with the reactive face 22 of another of the monopolar plates 10, 20, a reactive circuit 25 for the circulation of a reactive fluid.
[0051] Each monopolar plate 10, 20 has an inlet manifold 3, 6 of the reactive fluid for the entry of the reactive fluid into the reactive circuit 25 and an outlet manifold 7, 4 of the reactive fluid for the evacuation of the reactive fluid having passed through the reactive circuit 25.
[0052] The reagent circuit 25 comprises a plurality of reagent conduits 24.
[0053] The reagent circuit 25 further comprises a reagent fluid distribution circuit fluidly connecting the inlet collector port 3, 6 of the reactive fluid to the reactive conduits 24.
[0054] The reagent circuit 25 further includes a reagent fluid evacuation circuit fluidically connecting the outlet manifold port 7, 4 of the cooling fluid to the reagent conduits 24.
[0055] The plurality of reagent channels 24 is intended to face a diffusion layer of the Membrane Electrode Assembly 16.
[0056] The plurality of cooling conduits 14 extends over a surface substantially aligned with that in which the plurality of reagent conduits 24 extends.
[0057] The cooling fluid distribution circuit 13 and the cooling fluid evacuation circuit are each arranged on a peripheral area of the monopolar plate 10, 20, being in particular around the surface in which the plurality of cooling conduits 14 extend.
[0058] The first end plate 11 is fixed or welded to one of the monopolar plates 10, 20 of the first cell 301.
[0059] The second end plate 21 is fixed or welded to one of the monopolar plates 10, 20 of the last cell 302.
[0060] The sealing plate 21 includes an electric current collection face.
[0061] The electric current collection face is intended to face a plate electric current collector.
[0062] The monopolar plate 10, 20 has a light 2 fluidly connecting the inlet manifold 3, 6 of the reactive fluid to the reactive circuit 25 and / or fluidly connecting the outlet manifold 7, 4 of the reactive fluid to the reactive circuit 25.
[0063] Figure 1 shows two cells 30, namely the first cell 301 and the last cell 302 of a fuel cell stack. The stack may include other cells 30 in addition to the first 301 and last 302 cells, which are then stacked between the first cell 301 and the last cell 302.
[0064] Fig. 2 represents, in cross-section, part of one of the monopolar plates 10, 20 of the assembly [Fig. 1].
[0065] Fig. 3 represents one of the monopolar plates 10, 20 of the first cell 301 or the last cell 302.
[0066] In the example of [Fig.3], the distribution section is equal to the area L x H less the area occupied by the six embossments 41 of the monopolar plate 10, 20 and / or of the first end plate 11 and / or of the second end plate 21.
[0067] The other cells of the stack have, for example, fewer than six embossments, for example between 1 and 4 embossments, which makes it possible to limit the flow of the cooling fluid at the level of the first cell 301 and last cell 302.
Claims
1. Demands Assembly (1) comprising a stack of a plurality of proton exchange membrane fuel cell or electrolyzer cells (30), the stack being sandwiched between a first end plate (11) and a second end plate (21), the plurality of cells (30) comprising a first cell (301) at a first end of the stack and a last cell (302) at a second end of the stack, each cell (30) comprising two monopolar plates (10, 20), respectively an anodic plate (10) and a cathodic plate (20), each monopolar plate (10, 20) comprising a reactive face (22) and a cooling face (23) opposite to each other, the reactive face (22) being intended to face an Electrode Membrane Assembly (16), the cooling face (23) of each monopolar plate (10, 20) being intended to to form,together with the cooling face (23) of another of the monopolar plates (10, 20) or with the first end plate (11) or with the second end plate (21), a cooling circuit (15) for the circulation of a cooling fluid (40), each monopolar plate (10, 20) having an inlet manifold port (5) of the cooling fluid for the entry of the cooling fluid into the cooling circuit (15) and an outlet manifold port (8) of the cooling fluid for the discharge of the cooling fluid having passed through the cooling circuit (15), the cooling circuit (15) having a plurality of cooling conduits (14), a distribution circuit (13) of the cooling fluid fluid fluidly connecting the inlet manifold port (5) of the cooling fluid,to the cooling ducts (14) and a cooling fluid drain circuit fluidly connecting the cooling fluid outlet manifold port (8) to the cooling ducts (14), the cooling fluid distribution circuit (13) and / or the cooling fluid drain circuit (26) of the first (301) and last (302) cells each having a restriction configured to limit the flow of cooling fluid entering the cooling ducts (14) and / or exiting the ducts, cooling (14), compared to the other cells (30) in the stack.
2. Assembly (1) according to the preceding claim, the inlet manifold port (5) of the cooling fluid opening into the distribution circuit (13) of the cooling fluid via a distribution section, the distribution section being considered in a plane cutting a first gasket groove (9) formed on the reactive face (22) and surrounding the inlet manifold port (5) of the cooling fluid, the distribution section of the distribution circuit (13) of the cooling fluid of the first cell (301) and / or the last cell (302) being smaller than that of the distribution circuits (13) of the cooling fluid of the other cells (30).
3. Assembly (1) according to any one of the preceding claims, the outlet manifold port (8) of the cooling fluid opening into the cooling fluid drain circuit, via a drain section, the drain section being considered in a plane cutting a second gasket groove formed on the reactive face (22) and surrounding the outlet manifold port (8) of the cooling fluid, the drain section of the cooling fluid drain circuit of the first cell (301) and / or the last cell (302) being smaller than that of the cooling fluid drain circuits of the other cells (30).
4. Assembly (1) according to any one of the preceding claims, the restriction being configured to reduce the flow rate of the cooling fluid entering the cooling ducts (14) and / or exiting the cooling ducts (14), by at least 20% to 50%, compared to the other cells (30) of the stack.
5. Assembly (1) according to any one of the preceding claims, the restriction being achieved by at least one plug inserted in the coolant drain circuit or in the coolant distribution circuit (13) of the first cell (301) and / or the last cell (302), the plug being in particular made of elastomeric material.
6. Assembly (1) according to any one of the preceding claims, each monopolar plate (10, 20) being produced by molding from a mold, the restriction being produced by molding by adding an insert into said mold.
7. Assembly (1) according to any one of the preceding claims, the reactive face (22) of each monopolar plate (10, 20) being intended to form, together with the reactive face (22) of another of the monopolar plates (10, 20), a reagent circuit (25) for the circulation of a reactive fluid, each monopolar plate (10, 20) having an inlet manifold orifice (3, 6) of the reactive fluid for the entry of the reactive fluid into the reactive circuit (25) and an outlet manifold orifice (7, 4) of the reactive fluid for the discharge of the reactive fluid having passed through the reactive circuit (25), the reactive circuit (25) having a plurality of reactive conduits (24), a reactive fluid distribution circuit fluidly connecting the inlet manifold orifice (3, 6) of the reactive fluid to the reactive conduits (24) and a reactive fluid discharge circuit fluidly connecting the outlet manifold orifice (7, 4) of the cooling fluid,to the reagent lines (24).
8. Assembly (1) according to the preceding claim, the plurality of reagent channels (24) being intended to face a diffusion layer of the Membrane Electrode Assembly (16), the plurality of cooling channels (14) extending in particular over a surface substantially aligned with that in which the plurality of reagent channels (24) extends.
9. Assembly (1) according to the preceding claim, the cooling fluid distribution circuit (13) and the cooling fluid evacuation circuit each being arranged on a peripheral area of the monopolar plate (10, 20), in particular around the surface in which the plurality of cooling conduits (14) extend.
10. Fuel cell or electrolyzer comprising an assembly (1) according to any one of the preceding claims.