Method for producing a stack plate of a humidifier, and stack plate
The method addresses the challenge of integrating separation and sealing in fuel cell humidifiers by using a semi-permeable membrane as a bonding agent, achieving efficient moisture transfer and sealing with reduced manufacturing complexity and cost.
Patent Information
- Application Number
- JP2025115487
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-07-10
- Filing Date
- 2025-07-09
- Publication Date
- 2026-01-27
AI Technical Summary
Existing humidifier technologies for fuel cell systems face challenges in efficiently separating water in exhaust gas from supply air while ensuring leak-tight sealing without additional manufacturing steps or bonding agents, and require complex assembly processes.
A method for manufacturing stack plates using a semi-permeable membrane as a bonding agent, combined with a plastic frame and gasket layer, allowing for integrated separation and sealing functions, enabling automated assembly and reduced manufacturing complexity.
The method results in a functionally integrated stack plate with efficient moisture transfer and sealing capabilities, reducing equipment needs and manufacturing time, thus lowering costs and improving performance.
Smart Images
Figure 2026012652000001_ABST
Abstract
Description
[Technical Field]
[0001] SUMMARY OF THE INVENTION The embodiments relate to a method for manufacturing a stack plate for a humidifier, particularly a stack plate for a humidifier of a fuel cell stack, as well as a humidifier stack plate.
[0002] This application claims the benefit of European Application No. 24187576.4, filed July 10, 2024, the entire disclosure of which is incorporated herein by reference for all purposes. [Background technology]
[0003] Humidifier technology for fuel cell systems focuses on the separation between the water in the exhaust gas of the fuel cell stack and the supply air for the fuel cell stack, using membrane elements that are stacked together to create a sufficient effective area for separation. A common solution is to assemble steel plates containing the membrane together, and finally overmold all the individual stack plates with liquid silicone rubber to achieve sealing functionality between each stack plate.
[0004] EP 1223629 discloses a fuel cell having a gasket lip made of a liquid rubber vulcanization material and integrally formed on the surface of a flat plate or a groove formed on the surface, the flat plate being an electrode. A flat surface portion having a predetermined width that contacts the electrolyte membrane portion or the ion exchange membrane is formed on at least one of a pair of gasket lips arranged to hold the electrolyte membrane portion or the ion exchange membrane therebetween.
[0005] European Patent No. 1391956 discloses a fuel cell having a membrane electrode assembly with a gasket for sealing reactant gases. The gasket is formed on the surface of the gas diffusion layer facing the separator. The gasket-forming portion of each gas diffusion layer has a lower porosity than the portion of the membrane in contact with the catalyst layer. Through-holes pass through both the first and second gas diffusion layers, and the gasket is placed on the first and second gas diffusion layers via the through-holes provided in each of the first and second gas diffusion layers.
[0006] U.S. Patent Application Publication No. 2011 / 0305967 discloses a fuel cell stack including a plurality of membrane electrode assemblies, a plurality of separators in intimate contact with the membrane electrode assemblies between the membrane electrode assemblies, and gaskets provided on the separators. Each separator includes an anode separator having a first through-hole and a cathode separator in contact with the anode separator and having a second through-hole. Each gasket includes a penetration portion that fills the first through-hole and penetrates the anode separator and cathode separator, and a sealing portion that is joined to the penetration portion and protrudes from the outer surfaces of the anode separator and cathode separator in the thickness direction of the anode separator and cathode separator. Summary of the Invention
[0007] The object of the present embodiment is to provide a method for manufacturing a stack plate of a humidifier, in particular a stack plate for a humidifier of a fuel cell stack.
[0008] A further object of this embodiment is to provide a stack plate for a humidifier manufactured by the method.
[0009] According to one aspect of this embodiment, this object is achieved by a method for manufacturing a stack plate of a humidifier, particularly for a fuel cell stack, comprising the steps of providing an airtight but moisture-permeable semi-permeable membrane, depositing a plastic layer forming a plastic frame on a first side of the semi-permeable membrane so that the semi-permeable membrane is positioned over a fluid passage in the plastic frame, and depositing a gasket layer forming a gasket on a second side of the semi-permeable membrane, the gasket being for sealing the stack plate to another stack plate, the second side facing the first side at least in some areas where the semi-permeable membrane is supported by the plastic frame on the first side.
[0010] According to one aspect of this embodiment, this object is achieved by a method for manufacturing a stack plate of a humidifier, particularly for a fuel cell stack, comprising the steps of providing an airtight but moisture-permeable semi-permeable membrane, depositing a plastic layer forming a plastic frame on a first side of the semi-permeable membrane so that the semi-permeable membrane is positioned over a fluid passage in the plastic frame, and depositing a gasket layer forming a gasket on a second side of the semi-permeable membrane, the gasket being for sealing the stack plate to another stack plate, the second side facing the first side at least in some areas where the semi-permeable membrane is supported by the plastic frame on the first side.
[0011] Advantageous embodiments are set forth in the dependent claims, the description and the drawings.
[0012] The proposed method focuses on a manufacturing strategy for creating stack plates made of plastic materials, including sealing functions and membrane overmolding / decorative molding. Advantageously, the primary separating element of each stack plate, i.e., the membrane, is used as part of a leak-tight joining element between two materials that typically cannot be joined or joined without additional manufacturing steps and / or additional bonding agents and / or additional mechanical joint connections, achieving multiple functionalities in one part: the separating function of the membrane, stackability through the rigid frame region, and the sealing function of the gasket. By using the membrane as a bonding agent, the gasket's sealing function has two mechanical effects: one through the injection of grout into the frame part and the other through penetration into the membrane. Advantageously, stackable frame parts including the gasket function can be manufactured in a fully automated production mode without manual support. The use of the membrane as a bonding agent also allows for independent changes in the order in which the plastic material or the gasket layer is injected first.
[0013] This allows the creation of a functionally integrated plastic part with separation, sealing function, and easy assembly due to its shape stability, using the membrane as a joining element. The gasket layer with sealing function is injected directly onto the membrane. The plastic layer is injected directly onto the opposite side of the membrane.
[0014] The membrane may be a semipermeable membrane that separates the dry feed air flow path from the wet exhaust gas flow path. The semipermeable membrane may be designed, for example, as a PFSA (perfluorosulfonic acid) membrane. Such membranes are also commonly used as proton exchange membranes. The membrane is airtight but moisture permeable.
[0015] As material for the plastic layer, glass fiber reinforced polypropylene (PP GF 30) or polyamide (PA9T) may advantageously be used.
[0016] Advantageously, the proposed method of manufacturing humidifier stack plates requires less equipment for manufacturing and fewer manufacturing steps resulting in shorter cycle times, reducing the investment required, thus providing cost and performance advantages in the market.
[0017] According to a preferred embodiment of the method, the gasket layer may be deposited as liquid silicone rubber or polyurethane foam. The polyurethane foam may be a one-component polyurethane foam. Additionally or alternatively, the polyurethane foam may form a closed-pore structure. These materials may advantageously be bonded to the membrane and form a stable gasket for sealing the stack plates to each other when stacked in the humidifier.
[0018] According to a preferred embodiment of the method, after the step of depositing the plastic layer on the first side of the semipermeable membrane, in particular after hardening the plastic layer, the method may further comprise the step of forming, by hydraulic ejector action, recesses and corresponding protrusions in the plastic layer perpendicular to the first and second sides of the semipermeable membrane, so that in the region of each recess the semipermeable membrane comprises an opening, thereby allowing the plastic layer to be formed on the frame in a stabilizing design in one manufacturing step.
[0019] According to a preferred embodiment of the method, after the step of depositing the plastic layer on the first side of the semipermeable membrane, in particular after hardening the plastic layer, the method may further comprise the step of forming, by hydraulic ejector action, recesses and corresponding protrusions in the plastic layer perpendicular to the first and second sides of the semipermeable membrane, so that in the region of each recess the semipermeable membrane comprises an opening, thereby allowing the plastic layer to be formed on the frame in a stabilizing design in one manufacturing step.
[0020] According to a preferred embodiment, the method may further comprise the step of forming a grid layer on the second side of the semipermeable membrane on which the gasket layer is deposited. Advantageously, the grid can be provided in the same manufacturing step to influence airflow between the stack plates for efficient moisture transport through the membrane.
[0021] The proposed stack plate includes stack plates made of a plastic material, including a sealing function and a membrane overmolding / decorative molding. Advantageously, the primary separating element of each stack plate, i.e., the membrane, is used as part of a leak-tight joining element between two materials that typically cannot be joined or leak-tightly joined without additional manufacturing steps and / or additional bonding agents and / or additional mechanical connections, achieving multiple functions in one component: the separating function of the membrane, stackability through the rigid frame region, and the sealing function of the gasket. By using the membrane as a bonding agent, the gasket's sealing function has two mechanical effects: one through grout injection into the frame components and the other through penetration into the membrane.
[0022] This makes the stack plate a functional integrated plastic part, using the membrane as a joining element, with separation, sealing function and easy assembly possibility due to its shape stability.
[0023] The membrane may be a semipermeable membrane that separates the dry feed air flow path from the wet exhaust gas flow path. The semipermeable membrane may be designed, for example, as a PFSA (perfluorosulfonic acid) membrane. Such membranes are also commonly used as proton exchange membranes. The membrane is airtight but moisture permeable.
[0024] As material for the plastic layers of the plastic frame, glass fiber reinforced polypropylene (PP GF 30) or polyamide (PA9T) may advantageously be used.
[0025] According to a preferred embodiment of the stack plate, the gasket may comprise silicone rubber or polyurethane. The polyurethane may be a one-component polyurethane. Additionally or alternatively, the polyurethane may have a closed pore structure. These materials may be advantageously bonded to the membrane to form a stable gasket for sealing the stack plates to each other when stacked in the humidifier.
[0026] According to a preferred embodiment of the stack plate, the plastic frame may have a rectangular shape and the gaskets may be arranged on opposite short ends of the semipermeable membrane or on opposite long ends of the semipermeable membrane. Advantageously, a humidifier stack can be assembled comprising stack plates in which the fluid passages for the dry supply air and the wet exhaust gas are arranged alternately in a cross direction in successive stack plates.
[0027] According to a preferred embodiment of the stack plate, the stack plate may further comprise a grid layer arranged on the second side of the semipermeable membrane to which the gasket is bonded. Advantageously, the grid can be provided in the same manufacturing step to influence airflow between the stack plates for efficient moisture transfer through the membranes.
[0028] According to a preferred embodiment of the stack plate, a plastic frame may be circumferentially disposed on the outer edges of the longitudinal and lateral ends of the semipermeable membranes, in this way the stack plate is stabilized by the frame for proper assembly into the humidifier stack.
[0029] According to a preferred embodiment of the stack plate, gaskets may be disposed on opposite short edges of the semipermeable membrane, so that a fluid passageway may be provided through the long edges of the stack plate.
[0030] According to a preferred embodiment of the stack plate, the gasket may be arranged on the outer edge of the short ends of the semipermeable membrane, thereby providing maximum space for fluid passage through the long ends of the stack plate.
[0031] According to a preferred embodiment of the stack plate, gaskets may be arranged on opposite longitudinal ends of the semipermeable membrane, whereby a fluid passageway may be provided through the lateral ends of the stack plate.
[0032] According to a preferred embodiment of the stack plate, the gaskets may be arranged on the outer edges of the longitudinal ends of the semipermeable membranes, thereby providing maximum space for fluid passage through the lateral ends of the stack plate.
[0033] The present embodiments, together with these and other objects and advantages, can be best understood from the following detailed description of exemplary embodiments, but are not limited to these embodiments. [Brief explanation of the drawings]
[0034] [Figure 1] 2 is a plan view of a stack plate of a humidifier, in particular for a humidifier of a fuel cell stack, according to an embodiment, viewed from a second side, showing section line AA. FIG. [Figure 2] 2 shows the stack plate in cross section AA according to FIG. 1. [Figure 3] 10 is a plan view of a stack plate according to another embodiment seen from a second side, showing the cross-section line BB. FIG. [Figure 4] 4 shows the stack plate in cross section BB according to FIG. 3. [Figure 5] 1 with a grid layer according to a further embodiment. [Figure 6] 1 is a flowchart of a method for manufacturing a stack plate for a humidifier, in particular for a humidifier of a fuel cell stack, according to an embodiment. [Figure 7]10 is a flowchart of a method for manufacturing a stack plate according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0035] In the drawings, like elements are marked with the same reference numerals. The drawings are merely schematic representations and are not intended to depict specific parameters of the embodiments. Also, the drawings are intended to depict only typical embodiments and should not be considered as limiting the scope of the embodiments.
[0036] FIG. 1 is a plan view of a stack plate 100 for a humidifier, in particular for a humidifier of a fuel cell stack, according to an embodiment, viewed from a second side 14, with section line AA indicated.
[0037] The stack plate 100 includes a plastic frame 22 that surrounds a semipermeable membrane 10 disposed over a fluid passageway 50 of the frame 22. The frame 22 is bonded to a first side 12 of the membrane 10. A gasket 32 is bonded to a second side 14 opposite the first side 12 in at least some regions 38 where the membrane 10 is supported by the frame 22 disposed on the first side 12.
[0038] The frame 22 has a rectangular shape for easy assembly of the humidifier stack with the stack plates 100. The frame 22 provides mounting holes 42 at all four corners for inserting connecting rods to align and secure the stacked stack plates 100 in the humidifier stack. In the embodiment shown in Figure 1, gaskets 32 are disposed on the opposing short ends 16, 18 of the membrane 10, particularly on the outer edges of the short ends 16, 18 of the membrane 10.
[0039] The frame 22 is formed circumferentially around the outer edges of the longitudinal and lateral ends 16, 17, 18, 19 of the membrane 10.
[0040] The frame 22 presents grooves 36 on its rear longitudinal edges 17, 19 so that when the stack plate 100 is stacked with another stack plate 100, which has gaskets 32 disposed on the opposing longitudinal edges 17, 19 of the membrane 10, as shown in Figure 3, the gaskets 32 of the other stack plate 100 can cooperate with the grooves 36.
[0041] A fluid passageway 50 is provided on the second side 14 of the membrane 10. Either wet exhaust gas or dry feed air enters at one of the longitudinal ends 17,19 and exits at the other of the longitudinal ends 19,17.
[0042] As shown in FIG. 3, when gaskets 32 are placed on the opposing longitudinal ends 17,19, a fluid passageway 50 for dry feed air or wet exhaust gas is provided through the lateral ends 16,18.
[0043] The frame 22 may be formed by a plastic layer 20 deposited on the first side 12 of the membrane 10. The gasket 32 may be formed by a gasket layer 30 deposited on the second side 14 of the membrane 10 opposite the first side 12 in at least some areas 38 where the membrane 10 is supported by the plastic frame 22 on the first side 12.
[0044] The membrane 10 may be a semipermeable membrane that separates the dry feed air flow path from the wet exhaust gas flow path. The semipermeable membrane may be designed, for example, as a PFSA (perfluorosulfonic acid) membrane. Such membranes are also commonly used as proton exchange membranes. The membrane is airtight but moisture permeable.
[0045] As material for the plastic frame 22, advantageously glass-fiber reinforced polypropylene, for example PP GF 30, or polyamide, for example PA9T, may be used.
[0046] The gasket 32 may comprise silicone rubber or polyurethane. In particular, the polyurethane may be a one-component polyurethane. Alternatively or additionally, the polyurethane may have a closed pore structure.
[0047] In FIG. 2, the stack plate 100 is shown in cross section AA according to FIG.
[0048] Gasket 32 is seen in cross-section on second side 14 of membrane 10. Frame 22 is seen in cross-section on first side 12 of membrane 10. Gasket 32 is positioned in an area 38 of membrane 10 that is supported by frame 22 on its backside.
[0049] The frame 22 presents a structured cross-section with recesses 26 and corresponding protrusions 28. In the region of the recesses 26, the membrane 10 is provided with openings 11. Such a structured cross-section allows the stack plates 100 to be stacked accordingly by inserting the protrusions 28 of a subsequent stack plate 100 into the recesses 26 of the current stack plate 100. Thereby, a tight connection between successive stack plates 100 may be achieved.
[0050] The peripheral grooves 36 in the frame 22 serve to accommodate the gasket 32 of the adjacent second stack plate 102 in the region 38 of the first stack plate 100 that is free of a gasket 32 on the second side 14. That is, when a gasket 32 is present on the short ends 16, 18 of the stack plate 100, the grooves 36 of the frame 22 on the long ends 17, 19 accommodate the gasket 32 of the adjacent stack plate 102.
[0051] FIG. 3 is a plan view of another embodiment of a stack plate 102 from the second side 14, with section line BB indicated.
[0052] 1, but the gaskets 32 are formed on the opposing longitudinal ends 17, 19 of the membrane 10, in particular on the outer edges of the longitudinal ends 17, 19, instead of on the lateral ends 16, 18. Correspondingly, fluid passages 50 for dry feed air or wet exhaust gas are provided through the lateral ends 16, 18.
[0053] 4, the stack plate 102 is shown in cross section BB according to FIG. 3. The cross-sectional structure of the frame 22 and the gasket 32 provided on the membrane 10 is the same as that of the stack plate 100 shown in FIG.
[0054] In the humidifier stack, stack plates 100 according to Figures 1 and 2 with gaskets 32 on their short ends 16, 18 are alternately stacked with stack plates 102 according to Figures 3 and 4 with gaskets 32 on their long ends 17, 19. This allows the humidifier stack to be provided with one of wet exhaust gas and dry supply air on the long side of the humidifier stack and the other on the short side. Membrane 10 separates the wet exhaust gas from the dry supply air and allows moisture transfer from the wet exhaust gas to the dry supply air.
[0055] In FIG. 5 the stack plate 100 according to FIG. 1 is shown with a grid layer 40 according to a further embodiment.
[0056] A grid layer 40 is disposed on the second side 14 of the membrane 10 on which the gasket 32 is provided. Advantageously, the grid may be provided to influence air flow between the stack plates 100 for efficient moisture transfer through the membrane 10.
[0057] 5, the grid layer 40 exhibits a diagonal pattern. Other patterns for the grid layer may be advantageously used.
[0058] FIG. 6 shows a flow chart of a method for manufacturing stack plates 100, 102 for a humidifier, in particular for a humidifier of a fuel cell stack, according to an embodiment.
[0059] According to an embodiment, the stack plates 100, 102 can be manufactured in step S100 by providing a semipermeable membrane 10 that is placed over the fluid passage 50 of the plastic frame 22, the membrane 10 being intended to be placed between the plastic frame 22 and the gasket 32.
[0060] In step S102, a plastic layer 20 forming a frame 22 is deposited on the first side 12 of the membrane 10.
[0061] In step S104, a gasket layer 30 of liquid silicone rubber forming a gasket 32 is deposited on the second side 14 of the membrane 10 opposite the first side 12 in at least some areas 38 where the membrane 10 is supported by the plastic frame 22 on the first side 12.
[0062] In a further optional step S106, a grid layer 40 may be formed on the second side 14 of the membrane 10 on which the gasket layer 30 has been deposited. The grid layer 40 may advantageously not be bonded to the second side 14 of the membrane 10.
[0063] The order in which the different manufacturing steps are provided first is not essential: in particular, the gasket layer 30 may be deposited first, before the plastic layer 20 is deposited.
[0064] In a further embodiment, the grid layer 40 may be provided first, before depositing the plastic layer 20 and the gasket layer 30 .
[0065] Furthermore, after depositing the plastic layer 20 on the first side 12 of the membrane 10, and particularly after the plastic layer 20 has hardened, a hydraulic ejector action may be used to form recesses 26 and corresponding protrusions 28 in the plastic layer 20 that are perpendicular to the first side 12 and the second side 14 of the membrane 10.
[0066] Additionally, the membrane 10 may be cut at its periphery parallel to the compression injection mold, particularly the compression injection mold of the plastic layer 20 .
[0067] FIG. 7 shows a flow chart of a method for manufacturing stack plates 100, 102 according to another embodiment.
[0068] In another embodiment, step S200 corresponds to step S100 of FIG. 6, in which membrane 10 is provided.
[0069] Step S202 also corresponds to step S102 in FIG. 6, in which a plastic layer 20 forming a frame 22 is deposited on the first side 12 of the membrane 10.
[0070] However, in step S204, a gasket layer 30 of polyurethane foam forming a gasket 32 is deposited on the second side 14 of the membrane 10 opposite the first side 12 in at least some areas 38 where the membrane 10 is supported by the plastic frame 22 on the first side 12. In particular, the polyurethane foam may be a one-component polyurethane foam. Alternatively or additionally, the polyurethane foam may form a closed pore structure.
[0071] As in the embodiment shown in FIG. 6, the order of step S202 of depositing plastic layer 20 and step S204 of depositing gasket layer 30 may be interchanged. [Explanation of symbols]
[0072] 10 membrane 11 Opening 12 First Side 14 Second Side 15 Thickness 16 Longitudinal end 17 Short side end 18 Longitudinal end 19 Short side end 20 plastic layers 22 frames 24 Thickness 26 Recess 28 Convex part 30 gasket layers 32 Gasket 34 Thickness 36 Groove 38 areas 40 Grid Layers 42 mounting holes 50 Fluid passage 100 stack plates 102 Stack Plate S100 membrane provided S102 Plastic layer deposition S104 Deposition of liquid silicone rubber as a gasket layer S106 Grid Layer Provision S200 membrane provided S202 Plastic layer deposition S204 Deposition of polyurethane foam as a gasket layer
Claims
1. A method for manufacturing a humidifier stack plate (100, 102), in particular for a fuel cell stack, comprising the steps of: Providing an airtight but moisture-permeable semi-permeable membrane (10); depositing a plastic layer (20) forming the plastic frame (22) on a first side (12) of the semipermeable membrane (10) such that the semipermeable membrane (10) is positioned over a fluid passageway (50) of the plastic frame (22); depositing a gasket layer (30) forming a gasket (32) on the second side (14) of the semipermeable membrane (10); The gasket (32) is for sealing the stack plate (100, 102) to another stack plate (100, 102), and the second side (14) faces the first side (12) at least in some areas (38) where the semipermeable membrane (10) is supported by the plastic frame (22) on the first side (12).
2. The method of claim 1 , wherein the gasket layer (30) is deposited as a liquid silicone rubber.
3. 10. The method of claim 1, wherein the gasket layer (30) is deposited as a polyurethane foam, the polyurethane foam being a one-component polyurethane foam and / or the polyurethane foam forming a closed pore structure.
4. 2. The method of claim 1, further comprising, after the step of depositing the plastic layer (20) on the first side (12) of the semipermeable membrane (10), forming recesses (26) and corresponding protrusions (28) in the plastic layer (20) perpendicular to the first side (12) and the second side (14) of the semipermeable membrane (10) by hydraulic ejector action, such that in the region of each of the recesses (26), the semipermeable membrane (10) includes openings (11).
5. 10. The method of claim 1, further comprising cutting the semipermeable membrane (10) at a periphery parallel to the compression injection mold of the plastic layer (20).
6. The method of claim 1, further comprising forming a grid layer (40) on the second side (14) of the semipermeable membrane (10) on which the gasket layer (30) is deposited.
7. A humidifier stack plate (100, 102) manufactured by the method of claim 1, The semipermeable membrane (10); a plastic frame (22) surrounding the semipermeable membrane (10) disposed on a fluid passage (50) of the plastic frame (22), the plastic frame (22) being joined to the first side (12) of the semipermeable membrane (10); and a gasket (32) joined to the second side (14) opposite the first side (12) in at least some of the regions (38) where the semipermeable membrane (10) is supported by the plastic frame (22) on the first side (12).
8. The stack plate according to claim 7, wherein the gasket (32) comprises silicone rubber or polyurethane, the polyurethane being a one-component polyurethane, and / or the polyurethane having a closed pore structure.
9. The plastic frame (22) has a rectangular shape, 8. The stack plate of claim 7, wherein the gaskets (32) are arranged on opposing short ends (16, 18) of the semipermeable membrane (10) or on opposing long ends (17, 19) of the semipermeable membrane (10).
10. The stack plate of claim 7, further comprising a grid layer (40) disposed on the second side (14) of the semipermeable membrane (10) to which the gasket (32) is bonded.