Electrolyzer stack, electrolysis system and method for operating electrolysis system

Abstract

The invention relates to an electrolyzer stack, an electrolysis system and a method for operating an electrolysis system. A spring plate assembly. The assembly includes spring plates, wherein each spring plate has: a perimeter section extending in a first plane; at least one bridge section extending from a first portion of the perimeter section to a second portion of the perimeter section; and a spring element extending from the at least one bridge section. A first pair of adjacent spring plates is configured to engage a corresponding one of the perimeter sections when stacked in a first configuration, and the first pair of adjacent spring plates is configured to engage a corresponding one of the plurality of spring elements when stacked in a second configuration.

Description

Technical Field

[0001] The present disclosure relates generally to electrolyzers, and more particularly to an electrolyzer stack including a cell block and a spring plate assembly for applying force to the cell block, an electrolysis system including such an electrolyzer stack, and a method for operating such an electrolysis system. Background Art

[0002] An electrolyzer is an electrochemical device that converts water into hydrogen and oxygen using an electrolysis process. Electrolyzers are commonly used to produce hydrogen. Hydrogen is used in many industrial applications, such as the production of ammonia. Electrolyzers can be used for localized hydrogen production, for example as a fuel for vehicles equipped with hydrogen fuel cells. Electrolyzers can also be used to store energy from dynamic power sources, such as wind turbines and solar cells. Summary of the invention

[0003] A spring plate assembly is disclosed herein. The assembly includes spring plates, wherein each spring plate has: a perimeter segment extending in a first plane; at least one bridge segment extending from a first portion of the perimeter segment to a second portion of the perimeter segment; and a spring element extending from the at least one bridge segment. A first pair of adjacent spring plates are configured to engage corresponding ones of the perimeter segments when stacked in a first configuration, and the first pair of adjacent spring plates are configured to engage corresponding ones of the spring elements when stacked in a second configuration.

[0004] Another aspect of the present disclosure may be wherein each spring element comprises a metal bead.

[0005] Another aspect of the present disclosure may be wherein the metal bead comprises at least one of a cylindrical or conical shape.

[0006] Another aspect of the present disclosure may be wherein the distal portion of each spring element defines an opening through one of the spring plates.

[0007] Another aspect of the present disclosure may include a seal located in the perimeter segment, the seal forming a continuous ring around the spring element.

[0008] Another aspect of the present disclosure may be wherein the perimeter segment and the at least one bridge segment extend in a single plane.

[0009] Another aspect of the present disclosure may be wherein each spring plate is formed from a single unitary piece of material and includes the same profile.

[0010] An electrolyzer stack is disclosed herein. The stack includes: an electrolyzer block having an electrolyzer configured to receive and convert water to form a hydrogen product stream; and a spring plate assembly having a spring plate positioned adjacent to the electrolyzer block. Each spring plate includes: a perimeter segment extending in a first plane; at least one bridge segment extending from a first portion of the perimeter segment to a second portion of the perimeter segment; and a spring element extending from the at least one bridge segment. A first pair of adjacent spring plates is configured to engage corresponding ones of the perimeter segments when stacked in a first configuration, and the first pair of adjacent spring plates is configured to engage corresponding ones of the spring elements when stacked in a second configuration.

[0011] Another aspect of the present disclosure may be wherein each spring element comprises a metal bead.

[0012] Another aspect of the present disclosure may be wherein the metal bead comprises at least one of a cylindrical or conical shape.

[0013] Another aspect of the present disclosure may be wherein the distal portion of each spring element defines an opening through one of the spring plates.

[0014] Another aspect of the present disclosure may include a seal located in the perimeter segment, the seal forming a continuous ring around the spring element, wherein the seal includes at least one of an elastomeric bead or a metal bead.

[0015] Another aspect of the present disclosure may include a compression plate disposed between the spring plate assembly and the electrolytic cell block, wherein a seal on each spring plate at least partially forms a pressurized cavity with the compression plate that, when pressurized, applies a force to compress the electrolytic cell block.

[0016] Another aspect of the present disclosure may include a first end plate disposed adjacent the spring plate assembly opposite the compression plate.

[0017] Another aspect of the present disclosure may include a second end plate disposed adjacent to the electrolytic cell block on a side opposite the compression plate, wherein the first end plate and the second end plate are coupled together to constrain expansion of the electrolyzer stack, including constraining expansion of the spring plate assembly in a direction away from the electrolytic cell block.

[0018] Another aspect of the present disclosure may include at least one tension element extending between the first end plate and the second end plate and at least partially coupling the first end plate and the second end plate together.

[0019] Another aspect of the present disclosure may be wherein the perimeter segment and the at least one bridge segment extend in a single plane.

[0020] Another aspect of the present disclosure may be wherein each spring plate is formed from a single unitary piece of material and includes the same profile.

[0021] A method of operating an electrolysis system is disclosed herein. The method introduces water into an electrolyzer stack having an electrolyzer block. The water in the electrolyzer block is electrolyzed to form a hydrogen product stream. The electrolyzer block is compressed using a spring plate assembly having a spring plate positioned adjacent to the electrolyzer block. Each spring plate includes: a perimeter segment extending in a first plane; at least one bridge segment extending from a first portion of the perimeter segment to a second portion of the perimeter segment; and a spring element extending from the at least one bridge segment. A first pair of adjacent spring plates is configured to engage corresponding perimeter segments in the perimeter segments when stacked in a first configuration, and the first pair of adjacent spring plates is configured to engage corresponding spring elements in the spring elements when stacked in a second configuration.

[0022] The present invention also includes the following technical solutions:

[0023] Solution 1. A spring plate assembly comprising:

[0024] a plurality of spring plates, wherein each of the plurality of spring plates comprises:

[0025] a perimeter segment extending in a first plane;

[0026] at least one bridge segment extending from a first portion of the perimeter segment to a second portion of the perimeter segment; and

[0027] a plurality of spring elements extending from the at least one bridge segment; and

[0028] wherein a first pair of adjacent spring plates among the plurality of spring plates are configured to engage corresponding ones of the perimeter segments when stacked in a first configuration, and wherein the first pair of adjacent spring plates are configured to engage corresponding ones of the plurality of spring elements when stacked in a second configuration.

[0029] Option 2. The spring plate assembly of Option 1, wherein each of the plurality of spring elements comprises a metal bead.

[0030] Option 3. The spring plate assembly of Option 2, wherein the metal bead comprises at least one of a cylindrical or conical shape.

[0031] Option 4. The spring plate assembly of Option 1, wherein a distal portion of each of the plurality of spring elements defines an opening through one of the plurality of spring plates.

[0032] Embodiment 5. The spring plate assembly according to embodiment 1, comprising a seal located in the peripheral section, the seal forming a continuous ring around the plurality of spring elements.

[0033] Embodiment 6. The spring plate assembly according to embodiment 1, wherein the perimeter segment and the at least one bridge segment extend in a single plane.

[0034] Embodiment 7. The spring plate assembly of embodiment 1, wherein each of the plurality of spring plates is formed from a single unitary piece of material and comprises an identical profile.

[0035] Solution 8. An electrolyzer stack comprising:

[0036] an electrolysis cell block comprising a plurality of electrolysis cells configured to receive and convert water to form a hydrogen product stream; and

[0037] a spring plate assembly having a plurality of spring plates positioned adjacent to the electrolytic cell block, wherein each of the plurality of spring plates comprises:

[0038] a perimeter segment extending in a first plane;

[0039] at least one bridge segment extending from a first portion of the perimeter segment to a second portion of the perimeter segment; and

[0040] a plurality of spring elements extending from the at least one bridge segment; and

[0041] wherein a first pair of adjacent spring plates among the plurality of spring plates are configured to engage corresponding ones of the perimeter segments when stacked in a first configuration, and wherein the first pair of adjacent spring plates are configured to engage corresponding ones of the plurality of spring elements when stacked in a second configuration.

[0042] Embodiment 9. The electrolyzer stack of embodiment 8, wherein each of the plurality of spring elements comprises a metal bead.

[0043] Embodiment 10. The electrolyzer stack of Embodiment 9, wherein the metal beads comprise at least one of a cylindrical or conical shape.

[0044] Embodiment 11. The electrolyzer stack of embodiment 8, wherein a distal end portion of each of the plurality of spring elements defines an opening through one of the plurality of spring plates.

[0045] Embodiment 12. The electrolyzer stack of embodiment 8, comprising a seal located in the perimeter segment, the seal forming a continuous ring around the plurality of spring elements, wherein the seal comprises at least one of an elastomeric bead or a metal bead.

[0046] Option 13. The electrolyzer stack according to Option 12 includes a compression plate arranged between the spring plate assembly and the electrolytic cell block, wherein the seal on each of the plurality of spring plates at least partially forms a pressurized chamber with the compression plate, and when pressurized, the pressurized chamber applies a force to compress the electrolytic cell block.

[0047] Embodiment 14. The electrolyzer stack according to embodiment 13 comprises a first end plate disposed adjacent to the spring plate assembly opposite to the compression plate.

[0048] Option 15. The electrolyzer stack according to Option 14 includes a second end plate arranged adjacent to the electrolytic cell block on a side opposite to the compression plate, wherein the first end plate and the second end plate are connected together to constrain the expansion of the electrolyzer stack, including constraining the expansion of the spring plate assembly in a direction away from the electrolytic cell block.

[0049] Option 16. The electrolyzer stack of Option 15, comprising at least one tension element extending between the first end plate and the second end plate and at least partially coupling the first end plate and the second end plate together.

[0050] Embodiment 17. The electrolyzer stack of Embodiment 8, wherein the perimeter segment and the at least one bridge segment extend in a common plane.

[0051] Embodiment 18. The electrolyzer stack of embodiment 8, wherein each of the plurality of spring plates is formed from a single unitary piece of material and comprises an identical profile.

[0052] Embodiment 19. A method of operating an electrolysis system, the method comprising:

[0053] introducing water into an electrolyser stack including electrolytic cell blocks;

[0054] electrolyzing water in the electrolysis cell block to form a hydrogen product stream; and

[0055] The electrolytic cell block is compressed using a spring plate assembly having a plurality of spring plates positioned adjacent to the electrolytic cell block, wherein each of the plurality of spring plates comprises:

[0056] a perimeter segment extending in a first plane;

[0057] at least one bridge segment extending from a first portion of the perimeter segment to a second portion of the perimeter segment; and

[0058] a plurality of spring elements extending from the at least one bridge segment; and

[0059] wherein a first pair of adjacent spring plates among the plurality of spring plates are configured to engage corresponding ones of the perimeter segments when stacked in a first configuration, and wherein the first pair of adjacent spring plates are configured to engage corresponding ones of the plurality of spring elements when stacked in a second configuration.

[0060] Option 20. The method according to Option 19 includes using a portion of the hydrogen product flow to pressurize the spring plate assembly to apply additional force to the electrolytic cell block. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 is a schematic diagram of an electrolysis system according to one or more embodiments of the present disclosure.

[0062] Figure 2 is a schematic top view of a portion of an electrolysis system including an electrolyzer stack according to one or more embodiments of the present disclosure.

[0063] Figure 3 It is along line 3-3 Figure 2 A cross-sectional view of the electrolyser stack depicted in FIG.

[0064] Figure 4A The diagram shows the Figure 3 An exemplary set of plates between the end plates and the compression plates of an electrolyser stack.

[0065] Figure 4B Picture shows Figure 4A A top view of one of the sets of plates.

[0066] Figure 4C is along Figure 4B A cross-sectional view taken along line 4C-4C.

[0067] Figure 5A The diagram shows the Figure 3 Another exemplary set of plates between the end plates and compression plates of an electrolyzer stack.

[0068] Figure 5B Picture shows Figure 5A A top view of one of the sets of plates.

[0069] Figure 5C is along Figure 5B A cross-sectional view taken along line 5C-5C.

[0070] Figure 6 is a flow chart of a method for operating an electrolysis system according to one or more embodiments of the present disclosure.

[0071] The drawings are not necessarily drawn to scale and may present somewhat simplified representations of various preferred features of the present disclosure as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes. The details associated with such features will be determined in part by the specific intended application and use environment. DETAILED DESCRIPTION

[0072] As required, detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely examples of the present disclosure that may be implemented in various and alternative forms. The drawings are not necessarily drawn to scale; some features may be enlarged or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to adopt the present disclosure in various ways.

[0073] Unless otherwise specifically indicated from the context, as used herein, the term "approximately" is understood to be within the normal tolerance range in the art, such as within 2 standard deviations of the mean. "Approximately" may be understood to be within 10%, 5%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. "Approximately" may alternatively be understood to imply the exact value stated. Unless otherwise clearly indicated from the context, the numerical values ​​provided herein are modified by the term "approximately".

[0074] Electrolyzers are classified into three main types: alkaline electrolyzers, solid oxide electrolyzers, and proton exchange membrane (PEM) electrolyzers. Alkaline electrolyzers use an alkaline solution as an electrolyte, such as potassium hydroxide (KOH) or sodium hydroxide (NaOH). Solid oxides use solid ceramic materials as electrolytes that conduct oxygen ions at high temperatures (typically about 800°C to 1000°C). In one example, a PEM electrolyzer includes an electrolytic cell block formed by a plurality of stacked electrolytic cells (e.g., in series), wherein each electrolytic cell (cell) includes various components, including various membrane electrode assembly (MEA) components. The MEA components include a solid polymer membrane (i.e., a proton exchange membrane or PEM) disposed between an anode and a cathode. The MEA components constituting the cathode include a catalyst layer disposed adjacent to a gas diffusion layer (GDL). Similarly, the MEA components constituting the anode include a catalyst layer disposed adjacent to a porous transport layer (PTL). The PEM selectively allows positively charged hydrogen ions to pass through the membrane between the anode and the cathode as part of the electrolysis process to convert water (H 2 O) into hydrogen (H 2 ) and oxygen.

[0075] The PEM electrolyzer can be designed to apply a force (e.g., a compressive force) to the electrolyzer block during operation to offset the increased pressure generated by converting liquid water into hydrogen gas, thereby operating more efficiently. This force helps prevent hydrogen leakage and reduces contact resistance along the electrolyzer block by offsetting dimensional changes (e.g., expansion or contraction) in the stack length (e.g., stack height) of the PEM electrolyzer. For example, changes in the stack length of the PEM electrolyzer may be caused by expansion, thermal expansion, and / or creep of various components, such as sealing gaskets of the electrolyzers that seal the electrolyzer block, and / or one or more of the various MEA components within the electrolyzer block. Certain current designs are ineffective due to expansion, thermal expansion, creep, and / or high pressure.

[0076] In high pressure electrolyzers, for example where hydrogen pressures of up to 30 bar (3 MPa) or more may be generated, the problem or concern of hydrogen leakage and / or reduced electrolysis efficiency may be further increased. In such electrolyzers, the increased pressure also increases the hardware used to apply forces to offset the dimensional changes in the stack length of the electrolyzer. The additional hardware increases the stack volume, weight, and design complexity of the electrolyzer.

[0077] Therefore, it is desirable to provide an electrolyzer stack, an electrolysis system including such an electrolyzer stack, and a method for operating such an electrolysis system that solves one or more of the aforementioned problems. In addition, other desirable features and characteristics of the various embodiments described herein will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.

[0078] The present disclosure relates generally to electrolyzers, and more particularly to electrolyzer stacks including an electrolytic cell block and a spring plate assembly for applying force to the electrolytic cell block, electrolytic systems including such electrolyzer stacks, and methods for operating such electrolytic systems.

[0079] In one or more embodiments of the present disclosure, an electrolyzer stack includes an electrolyzer block including a plurality of electrolyzers configured to receive and convert water to form a hydrogen product stream. In some embodiments, a spring plate assembly is configured for fluid communication with the hydrogen product stream and is operatively configured to apply a force to the electrolyzer block when pressurized by a portion of the hydrogen product stream.

[0080] In one or more embodiments of the present disclosure, the electrolyzer stack is part of an electrolysis system. The electrolysis system also includes a water source and a power source in communication with the electrolyzer stack. During operation of the electrolysis system, liquid water is fluidly transferred to the electrolyzer stack from the water source, and electricity is transferred to the electrolyzer stack from the power source. The electrolyzer stack uses electricity to convert liquid water raw materials to produce a hydrogen product stream by electrolysis. In some embodiments, a portion of the hydrogen product stream is fluidly transferred to the spring plate assembly, thereby pressurizing the spring plate assembly and increasing the force (e.g., compression force) on the electrolyzer block to exceed the force applied by the spring plate assembly itself to offset the pressure increase in the electrolyzer block due to converting the liquid water raw material into hydrogen. This force helps prevent hydrogen leakage and reduces the contact resistance along the electrolyzer block by offsetting the dimensional change (e.g., expansion or contraction) of the stack length (e.g., stack height) of the electrolyzer. For example, changes in the stack length of the electrolyzer may be caused by expansion, thermal expansion and / or creep of various components, such as sealing gaskets of the electrolyzers that seal the electrolyzer blocks, and / or one or more of the various membrane electrode assembly (MEA) components within the electrolyzer blocks.

[0081] In higher pressure hydrogen production applications, for example, where hydrogen pressures of up to 30 bar (3 MPa) or more may be generated in the electrolyzer block, the resulting hydrogen product stream will also be at a correspondingly higher pressure. In one or more embodiments of the present disclosure, the portion of the higher pressure hydrogen product stream that is fluidly delivered to the spring plate assembly further increases the pressure within the spring plate assembly, including the combined force applied to the electrolyzer block. This helps to further offset the increased pressure within the electrolyzer block.

[0082] When expansion, thermal expansion and / or creep occur, the stack spring can compensate for dimensional changes by automatically adjusting the length of the stack spring with a minimal change in spring force. Thus, the stack can maintain a nominally stable stacking force, and therefore, maintain sealing pressure and contact resistance.

[0083] In an exemplary embodiment, advantageously, because the spring plate assembly applies a higher force to counteract dimensional changes in the electrolytic cell block and / or electrolyzer stack, hydrogen leakage is reduced, minimized or prevented and thus electrolysis efficiency in the electrolytic cell block is improved.

[0084] Figure 1is a schematic diagram of an electrolysis system 10 according to one or more embodiments of the present disclosure. As shown, the electrolysis system 10 includes a water source 20, which is in fluid communication with an electrolyzer stack 40 via a pipeline 22 to provide a water feedstock for the electrolyzer stack 40. Unused, surplus and / or byproduct water is returned to the water source 20 from the electrolyzer stack 40 via a recycle flow pipeline 44. In addition, a power supply 30 and a power electronics device 50 are in communication with the electrolyzer stack 40 via pipelines 32 and 52, respectively. In one or more embodiments of the present disclosure, a hydrogen storage device 60 is in fluid communication with the electrolyzer stack 40 via a pipeline 42 to receive hydrogen product produced during electrolysis in the electrolyzer stack 40, as will be discussed in further detail below.

[0085] As shown, electrolyzer stack 40 receives electricity (i.e., electric current) from power source 30 via line 32 and water from water source 20 via line 22. Electrolyzer stack 40 converts water from water source 20 into hydrogen and oxygen by electrolysis using the electricity supplied by power source 30. Hydrogen is produced as hydrogen product stream 122 ( Figure 3 The hydrogen (shown) is output from the electrolyzer stack 40 and proceeds to the hydrogen storage device 60 via line 42.

[0086] During operation of the electrolysis system 10, the power source 30 supplies direct current to the electrolyzer stack 40. Examples of power sources include, but are not limited to, batteries, solar cells, DC generators, wind turbines, hydroelectric plants, and the like.

[0087] The power electronics 50 communicate with the electrolyzer stack 40 and are configured to control the operation of the electrolyzer stack 40. For example, the power electronics 50 may control the amount of voltage and current supplied from the power source 30 to the electrolyzer stack 40.

[0088] Figure 2 is a schematic top view of a portion of an electrolysis system 10 including an electrolyzer stack 40 according to one or more embodiments of the present disclosure. Figure 3 It is along line 3-3 Figure 2 A cross-sectional view of the electrolyzer stack 40 depicted in FIG. Figure 1-3 In one or more embodiments of the present disclosure, the electrolyzer stack 40 includes an electrolyzer block 70 and a spring plate assembly 80. The electrolyzer block 70 includes a plurality of electrolyzers 72 (e.g., electrolyzer electrolyzers) configured to receive and convert water to form a hydrogen product stream 122. The spring plate assembly 80 is in fluid communication with the hydrogen product stream 122 and is operatively configured to apply a force to the electrolyzer block 70 when pressurized by a portion of the hydrogen product stream 84. The spring plate assembly 80 overlies the electrolyzer block 70 and expands when pressurized to apply a force to the electrolyzer block 70 indirectly or directly.

[0089] The plurality of electrolytic cells 72 include a plurality of seals 74 and a plurality of separators 210. The electrolytic cells in the plurality of electrolytic cells 72 are stacked and electrically connected in series in an electrolytic cell block 70. Each electrolytic cell in the plurality of electrolytic cells 72 includes various components, including a membrane electrode assembly (MEA), a pair of separators, and a pair of seals.

[0090] The pair of separators (from the plurality of separators 210) contain flow channels that interface with the MEA and allow fluids (e.g., water, hydrogen, and oxygen) to flow to or from the MEA. Each separator is conductive and facilitates the flow of electrons (e - ) to help establish the circuit for the electrolysis process.

[0091] The MEA includes a solid polymer membrane (i.e., a proton exchange member or PEM), an anode (i.e., an anode-catalyst layer), and a cathode (i.e., a cathode-catalyst layer). The PEM is disposed between the anode-catalyst layer and the cathode-catalyst layer. The cathode-catalyst layer is disposed adjacent to a gas diffusion layer (GDL). Likewise, the anode-catalyst layer is disposed adjacent to a porous transport layer (PTL). The PEM contains an active zone where an electrochemical reaction for converting water to hydrogen by electrolysis occurs. The PEM selectively allows positively charged hydrogen ions to pass through the membrane between the anode and cathode as part of the electrolysis process to convert water into hydrogen and oxygen.

[0092] Each electrolytic cell is configured such that the MEA is disposed between the pair of separators. The pair of seals (from the plurality of seals 74) prevent fluid (e.g., water, hydrogen, and oxygen) from leaking from the interface between the MEA and the pair of separators. The pair of seals defines the MEA perimeter 79 ( Figure 2 ). The MEA perimeter 79 is the area where the fluid is confined before exiting the MEA via the pair of separators.

[0093] The MEA perimeter 79 is associated with the perimeter area 76. The perimeter area 76 is the area defined by the plurality of seals 74 and the MEA perimeter 79 of each of the plurality of seals 74. In other words, the MEA perimeter 79 is associated with one electrolytic cell and the perimeter area 76 is associated with the plurality of electrolytic cells 72.

[0094] As shown, electrolyzer stack 40 receives water from water source 20 via line 22 and receives electrical current from power source 30 via line 32. Electrolyzer stack 40 may receive electrical current via wiring, bus bars, and / or electrical connectors (not shown), where, for example, the electrical connectors are electrically coupled to terminal plate 160 (e.g., a first terminal plate).

[0095] Water advances into the electrolytic cell block 70 via the water inlet 179, which feeds the plurality of electrolytic cells 72 via the plurality of separators 210, and passes through the electrolytic cell block 70. The terminal plates 160 and 170, the plurality of separators 210, and each MEA in the plurality of electrolytic cells 72 create an electrical circuit that drives the electrolysis process when current is applied to the electrolytic cell block 70. When current passes through the plurality of electrolytic cells 72 between the terminal plates 160 and 170, the water advancing in the electrolytic cells 72 is converted into hydrogen and oxygen through the electrolysis process.

[0096] As shown, oxygen and unused, excess and / or byproduct water are removed from electrolytic cell 72 via water and oxygen outlet 200. Water and oxygen outlet 200 forwards the removed water to recycle flow line 44 which passes the water back to water source 20.

[0097] The hydrogen produced in the electrolysis cells 72 is forwarded to a hydrogen header 190. The hydrogen leaves the electrolyzer stack 40 from the hydrogen header 190 to form a hydrogen product stream 122. The hydrogen product stream 122 is forwarded through a hydrogen product line 120 which is coupled to the line 42 ( Figure 1 as shown) fluid connected.

[0098] As shown, a portion of the hydrogen product stream 122 or side stream 132 is fluidly delivered to the spring plate assembly 80 via the side stream line 130. In one or more embodiments of the present disclosure, this portion of the hydrogen product stream 84 is introduced to the spring plate assembly 80 and pressurizes the spring plate assembly 80. In an exemplary embodiment, the spring plate assembly 80 is pressurized at the same or substantially the same pressure as the hydrogen product stream 122. For example, the fluid circuit segment including the lines 120 and 130 between the electrolytic cell block 70 and the spring plate assembly 80 may be free of flow restricting valves or devices, or alternatively, if valves or other flow restricting devices are included in the lines 120 and 130, the valves or devices are opened at substantially maximum flow during operation of the electrolysis system 10.

[0099] When spring plate assembly 80 is pressurized, spring plate assembly 80 applies a force (e.g., a compressive force or a force in the direction of electrolytic cell block 70) directly or indirectly to compression plate 90 (e.g., a movable compression plate, such as upward or downward in the orientation shown), which helps to evenly distribute and transfer the force to electrolytic cell block 70. As shown, compression plate 90 is disposed adjacent to and between spring plate assembly 80 and electrolytic cell block 70, and, for example, can be moved toward electrolytic cell block 70 in response to the force applied by spring plate assembly 80 to transfer the force to electrolytic cell block 70.

[0100] In one or more embodiments of the present disclosure, the portion of the force applied by the spring plate assembly 80 through the hydrogen pressure is represented by the following equation:

[0101] F B = P B x A B (1)

[0102] Among them, F B is the force exerted by the spring plate assembly 80 on the compression plate 90 due to the hydrogen pressure, P B is the pressure of the hydrogen contained within the spring plate assembly 80, and A B A is the area of ​​physical contact between the spring plate assembly 80 and the compression plate 90. B The spring plate assembly 80 is defined by an area formed by an outer perimeter 82 (as discussed further below) of the spring plate assembly 80 that substantially overlaps the perimeter area 76 defined by the plurality of seals 74. B With A H2 The same or substantially the same as described below.

[0103] In one or more embodiments of the present disclosure, during operation of the electrolyzer stack 40, pressure builds up inside the electrolytic cell block 70 due to the generation of hydrogen, causing the electrolytic cell block to exert a force in an outward direction. This force is described by the following equation:

[0104] F H2 = P H2 x A H2 (2)

[0105] Among them, F H2 represents the total force from the hydrogen pressure, F H2 represents the total hydrogen pressure, and A H2 is the area defined by the perimeter area 76. H2 are the same because the electrolyzer cells in the plurality of electrolyzer cells are identical and are arranged as Figure 3 The alignment configuration stack shown in .

[0106] In some embodiments, electrolyzer stack 40 may expand (ie, increase in height) when electrolyzer cells 72 are subjected to forces caused by an increase in hydrogen pressure, if no opposing or reacting forces are otherwise applied to electrolyzer stack 40 .

[0107] Force F of spring plate assembly 80 B By applying an F H2 The opposite force to counteract the total force F H2 Because A B Equal to A H2 , and because the pressure of the spring plate assembly 80 is equal to the internal pressure of the electrolyzer stack 40, the compression plate 90 remains stationary. Therefore, the length of the electrolyzer stack 40 does not change, thereby remaining substantially dimensionally stable.

[0108] In some embodiments, the electrolyzer stack 40 includes an electrolytic cell block 70, a compression plate 90, a spring plate assembly 80, an end plate 100 (e.g., a first end plate), an end plate 110 (e.g., a second end plate), a hydrogen product line 120, a side stream line 130, a tension element 140, a terminal plate 160, a terminal plate 170, the plurality of electrolytic cells 72, and a plurality of seals 74.

[0109] As briefly discussed above, the electrolytic cell 72 correspondingly includes seals 74 that overlie one another to define a perimeter region 76 disposed about an active zone 78 of the electrolytic cell block 70. As used herein, the term "active zone" is understood to mean a zone or region where an electrochemical reaction for converting water into hydrogen by electrolysis occurs. As shown, a spring plate assembly 80 overlies the active zone 78 of the electrolytic cell block 70. As used herein, the term "overlies" is understood to mean that in one or more orientations of the electrolytic cell block 70, the spring plate assembly 80 is above the electrolytic cell block 70, while in other orientations, although the spring plate assembly 80 may not be above the electrolytic cell block 70, the spring plate assembly 80 is directly or indirectly adjacent to the electrolytic cell block 70. The spring plate assembly 80 has an outer perimeter 82 that substantially overlaps the perimeter region 76 defined by the plurality of seals 74. Outer perimeter 82 is identical (eg, aligned and matched) or substantially identical to MEA perimeter 79 .

[0110] As shown, the electrolytic cell block 70 is disposed adjacent to and between the terminal plates 160 and 170. On the side of the terminal plate 160 opposite the electrolytic cell block 70, the compression plate 90 is disposed adjacent to and between the terminal plate 160 and the spring plate assembly 80. Additionally, and as shown, the spring plate assembly 80 is disposed adjacent to and between the compression plate 90 and the end plate 100.

[0111] As discussed above, the spring plate assembly 80, when pressurized, applies a force to the compression plate 90, which is transmitted to the electrolytic cell block 70. In one or more embodiments of the present disclosure, the spring plate assembly 80 applies a force on an area of ​​the spring plate assembly 80 that is in physical contact with the compression plate 90. The area (i.e., the spring plate assembly area) is the portion of the spring plate assembly 80 that is in physical contact with the compression plate 90 within the perimeter area 76. That is, the spring plate assembly area is substantially aligned with and matches an area of ​​the perimeter area 76.

[0112] In an exemplary embodiment, the spring plate assembly 80 is formed by or otherwise includes a plurality of plates 81 stacked together. Each plate 81 can be formed by stamping a sheet of metal material, such as stainless steel or aluminum. Each plate 81 is formed from a single unitary piece of material and includes the same profile. For example, the plates 81 can be formed by a stamping process.

[0113] like Figures 4A-4C As shown in , each plate 81 includes a perimeter section 91 having a seal 83. The perimeter section 91 includes a planar portion and an outer edge of the plate 81. The seal 83 is at least partially defined by a channel formed in the plate 81, which forms a continuous ring around the perimeter section 91. The seal 83 is formed without holes in the channel to prevent the pressurized hydrogen from escaping from the pressurized cavity at least partially defined by the spring plate assembly 80. The seal 83 can be an elastomeric bead formed by a method such as dispensing, molding, or screen printing. In addition, the seal 83 can also be a metal bead seal, which includes a metal bead with a layer of elastomer on top of the bead. The metal bead can be formed by stamping or hydroforming as part of the process of manufacturing the plate 81. A thin layer of elastomer can be applied on top of the metal bead by dispensing, molding, or screen printing. In the example shown, the seals 83 in the uppermost and lowermost plates 81 engage the end plate 100 and the compression plate 90, respectively. The seal 83 prevents hydrogen from escaping from a central region defining a hydrogen cavity that is at least partially defined by a series of adjacently stacked seals 83, compression plates 90, and end plates 100 that are engaged with one another.

[0114] In the example shown, each spring element 85 is positioned along a bridge segment 87 in the plates 81. The bridge segment 87 comprises a strip of plate material that extends across each plate 81. In one example, the bridge 87 extends from a first portion of a perimeter segment 91 on a first side of each plate 81 to a second portion of the perimeter segment 91 on a second side of the plate 81. The perimeter segment 91 and the bridge segment 87 each extend in a common or single plane in a corresponding one of the plates 81.

[0115] The spring element 85 may include a force applying structure, such as a metal bead, extending from an edge of one of the bridge segments 87 and spaced apart from an adjacent one of the bridge segments 87. In one embodiment, the spring element 85 may include a cylindrical or conical profile having an opening at a distal portion opposite the bridge segment 87. The opening in the spring element also allows hydrogen to be evenly distributed within the spring plate assembly 80 between the end plate 100 and the compression plate 90. The perimeter segment 91 of each plate 81 includes at least one reference groove 89 to help align the plates 81 when the plates 81 are stacked to form the spring plate assembly 80. One feature of the reference groove 89 is to improve the alignment of the seal 83 to prevent leakage from the internal cavity in the spring plate assembly 80.

[0116] like Figure 4A As shown in , a first pair of adjacent spring plates 81 are configured to engage corresponding perimeter segments 91 when stacked in a first configuration, and a first pair of adjacent spring plates 81 are configured to engage corresponding spring elements 85 when stacked in a second configuration.

[0117] like Figure 3 As shown in FIG. 1 , on the side of the electrolytic cell block 70 opposite the spring plate assembly 80, the terminal plate 170 is disposed adjacent to and between the electrolytic cell block 70 and the end plate 110. The terminal plates 160 and 170 (i.e., a pair of terminal plates) are electrically conductive to allow electricity to pass through to the electrolytic cell block 70 to drive the electrolysis of water to form the hydrogen product stream 122.

[0118] As shown, the hydrogen product stream 122 passes through an opening or conduit in the end plate 110. The hydrogen product stream 122 is formed from hydrogen produced by the electrolysis of water. In addition, and as shown, the side stream line 130 is in fluid communication with the hydrogen product line 120 and the spring plate assembly 80. In an exemplary embodiment, the side stream line 130 is coupled to the hydrogen product line 120 and the spring plate assembly 80 to pass to the spring plate assembly 80 along a portion of the hydrogen product stream 84, as discussed above.

[0119] In an exemplary embodiment, tension element 140 and spring plate assembly 80 are coupled and cooperate to compress electrolytic cell block 70 by coupling end plates 100 and 110 together. End plates 100 and 110 are coupled together to constrain expansion of electrolyzer stack 40, including constraining expansion of spring plate assembly 80 in a direction away from electrolytic cell block 70. In an exemplary embodiment, this helps ensure that spring plate assembly 80 directs force toward electrolytic cell block 70 when pressurized.

[0120] In an exemplary embodiment, tension element 140 and spring plate assembly 80 further assist in providing additional force to electrolytic cell block 70 to ensure that a certain level of force is applied to seal 74 and active area 78 despite pressure fluctuations and / or dimensional changes in electrolytic cell block 70 that may occur during operation and / or startup of electrolysis system 10.

[0121] Figures 5A-5C Another exemplary spring plate assembly 180 is illustrated. Spring plate assembly 180 is similar to spring plate assembly 80 except as described below or shown in the accompanying drawings. Identical or similar parts will include the addition of a leading "1" to identify corresponding elements. Spring plate assembly 180 does not form a hydrogen cavity to help compress electrolytic cell block 70 like spring plate assembly 80, but instead utilizes the spring force from spring element 185 to compress electrolytic cell block 70.

[0122] In the illustrated example, each plate 181 in the spring plate assembly 180 includes a perimeter segment 191 with discrete spring elements 185 positioned along a bridge segment 187. The bridge segments 187 each include a strip of plate material extending across each plate 181 from a first side of the perimeter segment 191 to a second side of the perimeter segment 191 opposite the first side. The perimeter segment 191 of each plate 181 includes at least one reference groove 189 to help align the plates 181 when they are stacked to form the spring plate assembly 180.

[0123] Figure 6 is a flow chart of a method 400 for operating an electrolysis system 10 according to one or more embodiments of the present disclosure. The method 400 includes introducing (block 410) water to an electrolyzer stack 40 including an electrolytic cell block 70.

[0124] The method 400 continues by electrolyzing (block 420) the water in the electrolyzer block to form a hydrogen product stream. The spring plate assembly 80, 180 provides a compressive force to the electrolyzer block (block 430). In one exemplary embodiment, the spring plate assembly 80 is pressurized with a portion of the hydrogen product stream 84 to apply additional force to the electrolyzer block 70. In another exemplary embodiment, the spring plate assembly 180 itself is used to provide a compressive force to the electrolyzer block.

[0125] In an exemplary embodiment, the electrolysis system 10 is incorporated into or otherwise used in a vehicle, such as a motor vehicle. As used herein, "vehicle" is understood to mean a device configured for transporting people, things, objects, etc. Non-limiting examples of motor vehicles (e.g., internal combustion engine (ICE) vehicles, electric vehicles including battery and fuel cell vehicles, etc.) include land vehicles (e.g., cars, trucks, motorcycles, electric bicycles, buses, trains, etc.), aircraft (e.g., airplanes, helicopters, unmanned aerial vehicles, etc.), water vehicles (e.g., boats, watercraft, etc.), and amphibious vehicles (e.g., hovercraft, etc.). In addition, aspects of the present disclosure, such as the spring plate assembly 80, 180 and the separate spring plates 81, 181, are suitable for packaging between fuel cells and battery cells of a traction battery in a vehicle.

[0126] While the best modes for carrying out the disclosure have been described in detail, those familiar with the art to which this disclosure relates will recognize various alternative designs and embodiments for practicing the disclosure within the scope of the appended claims.

[0127] Any dimensions, configurations, etc. discussed herein may be varied as needed or desired from any values ​​or characteristics specifically mentioned herein or shown in the drawings for any embodiment.

[0128] It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments of the apparatus and assembly methods as discussed herein without departing from the scope or spirit of the present disclosure. Other embodiments of the present disclosure will be apparent to those skilled in the art by consideration of the specification and practice of the various embodiments disclosed herein. For example, the construction and function of some devices may be different from those described herein, and certain steps of any method may be omitted, performed in an order different from that specifically mentioned, or in some cases performed simultaneously or in sub-steps. In addition, certain aspects or features of the various embodiments may be modified or modified to create additional embodiments, and features and aspects of the various embodiments may be added to other embodiments or substituted for other features or aspects of other embodiments to provide yet further embodiments.

Claims

1. A spring plate assembly, comprising: a plurality of spring plates, wherein each of the plurality of spring plates comprises: a perimeter segment extending in a first plane; at least one bridge segment extending from a first portion of the perimeter segment to a second portion of the perimeter segment; and a plurality of spring elements extending from the at least one bridge segment; and wherein a first pair of adjacent spring plates among the plurality of spring plates are configured to engage corresponding ones of the perimeter segments when stacked in a first configuration, and wherein the first pair of adjacent spring plates are configured to engage corresponding ones of the plurality of spring elements when stacked in a second configuration.

2. The spring plate assembly according to claim 1, wherein: Each of the plurality of spring elements includes a metal bead.

3. The spring plate assembly according to claim 2, wherein: The metal beads include at least one of a cylindrical or conical shape.

4. The spring plate assembly according to claim 1, wherein: A distal end portion of each of the plurality of spring elements defines an opening through one of the plurality of spring plates.

5. The spring plate assembly of claim 1, comprising a seal located in the perimeter section, the seal forming a continuous ring around the plurality of spring elements.

6. The spring plate assembly according to claim 1, wherein: The perimeter segment and the at least one bridge segment extend in a single plane.

7. The spring plate assembly according to claim 1, wherein: Each of the plurality of spring plates is formed from a single unitary piece of material and includes an identical profile.

8. An electrolyzer stack comprising: an electrolysis cell block comprising a plurality of electrolysis cells configured to receive and convert water to form a hydrogen product stream; as well as a spring plate assembly having a plurality of spring plates positioned adjacent to the electrolytic cell block, wherein each of the plurality of spring plates comprises: a perimeter segment extending in a first plane; at least one bridge segment extending from a first portion of the perimeter segment to a second portion of the perimeter segment; and a plurality of spring elements extending from the at least one bridge segment; and wherein a first pair of adjacent spring plates among the plurality of spring plates are configured to engage corresponding ones of the perimeter segments when stacked in a first configuration, and wherein the first pair of adjacent spring plates are configured to engage corresponding ones of the plurality of spring elements when stacked in a second configuration.

9. The electrolyser stack according to claim 8, wherein: Each of the plurality of spring elements includes a metal bead.

10. The electrolyser stack of claim 9, wherein: The metal beads include at least one of a cylindrical or conical shape.

Images