Electrolyzer stack including passive compression, electrolysis system and method for operating electrolysis system

Abstract

An electrolyzer stack, an electrolysis system, and a method for operating an electrolysis system are provided. In one example, an electrolyzer stack includes an electrolysis cell block including a plurality of electrolysis cells configured to receive and convert water to form a hydrogen product stream. The bladder is in fluid communication with the hydrogen product stream and is operatively disposed to apply a force to the electrolysis cell block when pressurized by a portion of the hydrogen product stream.

Description

Technical Field

[0001] introduction

[0002] The present disclosure relates generally to electrolyzers, and more particularly to an electrolyzer stack including a cell block and a bladder 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

[0003] 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, for example, the production of ammonia. Electrolyzers can be used for local production of hydrogen, 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

[0004] An electrolyzer stack for an electrolysis system is provided. The electrolyzer stack includes an electrolyzer block and a bladder. The electrolyzer block includes a plurality of electrolyzers configured to receive and convert water to form a hydrogen product stream. The bladder is configured for fluid communication with the hydrogen product stream and is operatively arranged to apply a force to the electrolyzer block when pressurized by a portion of the hydrogen product stream.

[0005] In some embodiments, the electrolyzer stack further includes a side stream conduit providing fluid communication between the hydrogen product stream and the bladder to advance the portion of the hydrogen product stream to the bladder.

[0006] In some embodiments, the electrolyzer stack further comprises a compression plate disposed between the bladder and the electrolyzer block, wherein the bladder, when pressurized, applies a force to the compression plate, which transmits the force to the electrolyzer block.

[0007] In some embodiments, the electrolyzer stack further includes a first end plate disposed adjacent the bladder and opposite the compression plate.

[0008] In some embodiments, the electrolyzer stack of claim 4 further includes a second end plate disposed adjacent to the electrolyzer block on a side opposite to the compression plate, wherein the first end plate and the second end plate are connected together to constrain expansion of the electrolyzer stack, including constraining expansion of the bladder in a direction away from the electrolyzer block.

[0009] In some embodiments, the electrolyzer stack further includes a tension rod extending between the first end plate and the second end plate and at least partially connecting the first end plate and the second end plate together.

[0010] In some embodiments, the electrolyzer stack further includes a spring coupled to and cooperating with the tension rod to connect the first end plate and the second end plate together.

[0011] In some embodiments, the plurality of electrolytic cells respectively include a plurality of seals disposed between the compression plate and the second end plate and overlying each other to define a perimeter region disposed about an active zone of the electrolytic cell block.

[0012] In some embodiments, the capsule covers the active area of ​​the electrolytic cell block.

[0013] In some embodiments, the bladder has an outer perimeter that interfaces with the compression plate and substantially overlaps a perimeter area defined by the plurality of seals.

[0014] In some embodiments, the electrolyzer stack further includes a pair of terminal plates including a first terminal plate disposed between the electrolyzer block and the compression plate, and a second terminal plate disposed between the electrolyzer block and the second end plate, wherein the bladder covers the first terminal plate.

[0015] In some embodiments, the pair of terminal plates are configured to deliver electricity to the electrolyzer block to drive electrolysis of water to form a hydrogen product stream.

[0016] According to an alternative embodiment, an electrolysis system includes a water source, a power source, and an electrolyzer stack. The electrolyzer stack includes an electrolyzer block and a bladder. The electrolyzer block includes a plurality of electrolyzers in fluid communication with the water source to receive water and in communication with the power source to electrolyze the water to form a hydrogen product stream. The bladder is configured for fluid communication with the hydrogen product stream and is operatively arranged to apply a force to the electrolyzer block when pressurized by a portion of the hydrogen product stream.

[0017] In some embodiments, the electrolysis system further includes power electronics in communication with the electrolyzer stack and configured to control operation of the electrolyzer block to produce the hydrogen product stream.

[0018] In some embodiments, the electrolysis system further includes a recirculation flow line in fluid communication with the electrolyzer stack and the water source to recirculate a remaining portion of the water from the electrolyzer stack to the water source.

[0019] According to an alternative embodiment, a method for operating an electrolysis system is provided. The method includes: introducing water to an electrolyzer stack including an electrolyzer block; electrolyzing the water in the electrolyzer block to form a hydrogen product stream; and pressurizing a bladder with a portion of the hydrogen product stream to apply pressure to the electrolyzer block.

[0020] In some embodiments, the electrolyzer stack further includes a side stream conduit in fluid communication with the hydrogen product stream and the bladder, and wherein pressurizing includes advancing the portion of the hydrogen product stream along the side stream conduit to the bladder.

[0021] In some embodiments, the electrolyzer stack further includes a compression plate disposed between the bladder and the electrolyzer block, and wherein pressurizing includes pressurizing the bladder to apply a force to the compression plate, which transmits the force to the electrolyzer block.

[0022] In some embodiments, the electrolyzer stack further includes an end plate disposed adjacent the bladder and opposite the compression plate, and wherein pressurizing includes constraining expansion of the bladder in a direction away from the electrolyzer block using the end plate.

[0023] In some embodiments, the electrolysis system is incorporated into a vehicle, and the method further includes operating the electrolysis system in the vehicle.

[0024] The present disclosure also provides the following technical solutions:

[0025] 1. An electrolyzer stack comprising:

[0026] an electrolyzer block comprising a plurality of electrolyzers configured to receive and convert water to form a hydrogen product stream; and

[0027] A bladder is configured for fluid communication with the hydrogen product stream and operatively disposed to apply a force to the electrolyzer block when pressurized by a portion of the hydrogen product stream.

[0028] 2. The electrolyzer stack according to technical solution 1 further comprises a side stream conduit, which provides fluid connection between the hydrogen product flow and the capsule to enable the portion of the hydrogen product flow to advance to the capsule.

[0029] 3. The electrolyzer stack according to technical solution 1 further comprises a compression plate arranged between the bladder and the electrolytic cell block, wherein the bladder applies the force to the compression plate when pressurized, and the compression plate transfers the force to the electrolytic cell block.

[0030] 4. The electrolyzer stack according to Technical Solution 3 further comprises a first end plate, which is arranged adjacent to the bladder and opposite to the compression plate.

[0031] 5. The electrolyzer stack according to technical solution 4 further includes a second end plate, which is arranged adjacent to the electrolyzer block on a side opposite to the compression plate, wherein the first end plate and the second end plate are connected together to restrain the expansion of the electrolyzer stack, including restraining the expansion of the bladder in a direction away from the electrolyzer block.

[0032] 6. The electrolyzer stack according to Technical Solution 5 further comprises a stretch rod extending between the first end plate and the second end plate and at least partially connecting the first end plate and the second end plate together.

[0033] 7. The electrolyzer stack according to technical solution 6 further includes a spring, which is connected to the tension rod and cooperates with it to connect the first end plate and the second end plate together.

[0034] 8. An electrolyzer stack according to Technical Solution 5, wherein the plurality of electrolytic cells respectively include a plurality of seals, the plurality of seals being disposed between the compression plate and the second end plate and covering each other to define a peripheral area disposed around an active area of ​​the electrolytic cell block.

[0035] 9. The electrolyzer stack according to technical solution 8, wherein the capsule covers the active area of ​​the electrolytic cell block.

[0036] 10. The electrolyzer stack according to technical solution 9, wherein the bladder has an outer perimeter that abuts against the compression plate and substantially overlaps with the perimeter area defined by the plurality of seals.

[0037] 11. The electrolyzer stack according to Technical Solution 5 further comprises a pair of terminal plates, the pair of terminal plates comprising a first terminal plate arranged between the electrolytic cell block and the compression plate, and a second terminal plate arranged between the electrolytic cell block and the second end plate, wherein the sac covers the first terminal plate.

[0038] 12. An electrolyzer stack according to technical solution 11, wherein the paired terminal plates are configured to deliver electricity to the electrolyzer blocks to drive the electrolysis of water, thereby forming the hydrogen product stream.

[0039] 13. An electrolysis system comprising:

[0040] Water source;

[0041] Power supply; and

[0042] An electrolyzer stack comprising:

[0043] an electrolyzer block comprising a plurality of electrolyzers in fluid communication with the water source to receive water and in communication with the power source to electrolyze the water to form a hydrogen product stream; and

[0044] A bladder is configured for fluid communication with the hydrogen product stream and operatively disposed to apply a force to the electrolyzer block when pressurized by a portion of the hydrogen product stream.

[0045] 14. The electrolysis system according to technical solution 13 further comprises a power electronic device, which is connected to the electrolyzer stack and is configured to control the operation of the electrolyzer block to produce the hydrogen product flow.

[0046] 15. The electrolysis system according to technical solution 13 further comprises a recirculation flow pipeline, which is connected to the electrolyzer stack and the water source fluid to recirculate the remaining part of the water from the electrolyzer stack to the water source.

[0047] 16. A method for operating an electrolysis system, the method comprising:

[0048] introducing water into an electrolyser stack including said electrolyser blocks;

[0049] electrolyzing water in the electrolyzer block to form a hydrogen product stream; and

[0050] The bladder is pressurized with a portion of the hydrogen product stream to apply pressure to the electrolyser block.

[0051] 17. A method according to technical solution 16, wherein the electrolyzer stack further includes a side flow pipeline connected to the hydrogen product flow and the capsule fluid, and wherein pressurization includes allowing the portion of the hydrogen product flow to advance along the side flow pipeline to the capsule.

[0052] 18. A method according to technical solution 16, wherein the electrolyzer stack further includes a compression plate arranged between the bladder and the electrolyzer block, and wherein pressurizing includes pressurizing the bladder to apply the force to the compression plate, and the compression plate transfers the force to the electrolyzer block.

[0053] 19. A method according to technical solution 18, wherein the electrolyzer stack further includes an end plate, which is arranged adjacent to the bladder and opposite to the compression plate, and wherein pressurization includes using the end plate to constrain the expansion of the bladder in a direction away from the electrolytic cell block.

[0054] 20. The method according to technical solution 16, wherein the electrolysis system is incorporated into a vehicle, and wherein the method further comprises operating the electrolysis system in the vehicle.

[0055] The above features and advantages and other features and advantages of the present disclosure are readily apparent from the following detailed description of the best modes for carrying out the disclosure when taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a schematic illustration of an electrolysis system according to one or more embodiments of the present disclosure.

[0057] 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.

[0058] Figure 3 yes Figure 2 A cross-sectional view of the electrolyzer stack depicted in FIG. 3 along line 3 - 3 .

[0059] Figure 4 is a flow chart of a method for operating an electrolysis system according to one or more embodiments of the present disclosure.

[0060] The accompanying 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

[0061] As required, detailed embodiments of the present disclosure are disclosed herein; however, it will be understood that the disclosed embodiments are merely examples of the present disclosure, which may be embodied in various and alternative forms. The figures are not necessarily drawn to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein are not to 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.

[0062] Unless otherwise stated from the context, as used herein, the term "about" should be understood to be within the normal tolerance range in the art, such as within 2 standard deviations of the mean. "About" can be understood to be within 10%, 5%, 1%, 0.5%, 0.1%, 0.05% or 0.01% of the value. "About" can alternatively be understood to imply the exact value stated. Unless otherwise clear from the context, the numerical values ​​provided herein are modified by the term "about".

[0063] Electrolyzers are classified into three main types: alkaline electrolyzers, solid oxide electrolyzers, and proton exchange membrane (PEM) electrolyzers. Alkaline electrolyzers use alkaline solutions as electrolytes, 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 electrolyzer block formed by a plurality of stacked electrolyzers (e.g., in series), wherein each electrolyzer 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 into hydrogen and oxygen.

[0064] The PEM electrolyzer can be designed to apply a force (e.g., a compressive force) to the electrolyzer block during operation to counteract the increased pressure (s) generated by converting liquid water to hydrogen gas, thereby operating more efficiently. This force helps prevent hydrogen leakage and reduces contact resistance along the electrolyzer block by counteracting dimensional changes (e.g., expansion or contraction) in the stack length (e.g., stack height) of the PEM electrolyzer. Changes in the stack length of the PEM electrolyzer may be caused, for example, by swelling, thermal expansion, and / or creep of various components, such as, for example, one or more of the sealing gaskets that seal the electrolyzers in the electrolyzer block and / or various MEA components within the electrolyzer block. Some of the current designs are inefficient due to swelling, thermal expansion, creep, and / or high pressure.

[0065] 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.

[0066] Therefore, it is desirable to provide an electrolyzer stack that solves one or more of the above problems, an electrolysis system including such an electrolyzer stack, and a method for operating such an electrolysis system. 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.

[0067] The present disclosure relates generally to electrolyzers, and more particularly to an electrolyzer stack including an electrolyzer block and a bladder for applying force to the electrolyzer block, an electrolysis system including such an electrolyzer stack, and a method for operating such an electrolysis system.

[0068] 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. The bladder is configured for fluid communication with the hydrogen product stream and operatively arranged to apply a force to the electrolyzer block when pressurized by a portion of the hydrogen product stream.

[0069] In one or more embodiments of the present disclosure, the electrolyzer stack is part of an electrolysis system. The electrolysis system further includes a water source and a power source, which are configured to communicate with the electrolyzer stack. During operation of the electrolysis system, liquid water is fluidly delivered to the electrolyzer stack from the water source, and electricity is delivered 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 via electrolysis. A portion of the hydrogen product stream is fluidly delivered to the capsule, thereby pressurizing the capsule and applying a force (e.g., a compressive force) to the electrolyzer block to offset the pressure increase in the electrolyzer block generated by converting the liquid water raw material into hydrogen in the electrolyzer block. This force helps prevent hydrogen leakage and reduces the electrical 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. Changes in the stack length of the electrolyzer may be caused, for example, by bulging, thermal expansion and / or creep of various components, such as, for example, one or more of the sealing gaskets that seal the electrolyzers in the electrolyzer block and / or various membrane electrode assembly (MEA) components within the electrolyzer block.

[0070] In higher pressure hydrogen production applications, such as 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 fluidly delivered to the bladder further increases the pressure within the bladder, including the combined force applied to the electrolyzer block. This helps to further offset the increased pressure within the electrolyzer block.

[0071] In one or more embodiments of the present disclosure, the bladder may be used in conjunction with one or more stack springs to apply a combined force to the electrolyzer block via a compression plate. In such embodiments, the stack spring(s) apply a stack force to the electrolyzer block to mitigate the effects of stack compression force fluctuations and dimensional changes. Examples of dimensional changes include a decrease in sealing pressure and an increase in electrical contact resistance, which is caused by an increase in the distance between repeated electrolyzers (i.e., the electrolyzer-to-electrolyzer spacing).

[0072] When bulging, thermal expansion and / or creep occur, the stack spring can compensate for dimensional changes by automatically adjusting the length of the stack spring with minimal change in spring force. Thus, the stack can maintain a nominally stable stack force, and therefore maintain sealing pressure and contact resistance.

[0073] In exemplary embodiments, advantageously, hydrogen leakage is reduced, minimized or prevented and electrolysis in the electrolyzer block is improved due to the higher force(s) applied by the bladder to counteract any dimensional changes in the electrolyzer block and / or electrolyzer stack.

[0074] Figure 1 is a schematic view of an electrolysis system 10 according to one or more embodiments of the present disclosure. As illustrated, the electrolysis system 10 includes a water source 20, which is fluidly connected to an electrolyzer stack 40 via a conduit 22 to provide a water feedstock to the electrolyzer stack 40. Any unused, remaining and / or byproduct water is returned to the water source 20 from the electrolyzer stack 40 via a recirculation flow conduit 44. Additionally, a power source 30 and a power electronics 50 are in communication with the electrolyzer stack 40 via conduits 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 conduit 42 to receive hydrogen products produced during electrolysis in the electrolyzer stack 40, as will be discussed in further detail below. As illustrated, the electrolyzer stack 40 receives electricity (i.e., current) from the power source 30 via conduit 32 and receives water from the water source 20 via conduit 22. The electrolyzer stack 40 converts water from the water source 20 into hydrogen and oxygen via electrolysis using electricity supplied by the power source 30. The hydrogen is produced as a hydrogen product stream 122 (at Figure 3 ) is output from the electrolyzer stack 40 and advances to the hydrogen storage device 60 via pipeline 42.

[0075] 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 power plants, and / or the like.

[0076] The power electronics 50 are in communication 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.

[0077] 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 yes Figure 2 A cross-sectional view of the electrolyzer stack 40 depicted in FIG. 4 is taken along line 3 - 3 . Figures 1 to 3In one or more embodiments of the present disclosure, the electrolyzer stack 40 includes an electrolyzer block 70 and a bladder 80. The electrolyzer block 70 includes a plurality of electrolyzers 72 (e.g., electrolyzer cells) configured to receive and convert water to form a hydrogen product stream 122. The bladder 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 bladder 80 covers the electrolyzer block 70 and expands when pressurized to apply a force to the electrolyzer block 70 indirectly or directly.

[0078] The plurality of electrolytic cells 72 include a plurality of seals 74 and a plurality of separator plates 210. The electrolytic cells in the plurality of electrolytic cells 72 are stacked into an electrolytic cell block 70 and electrically connected in series. Each electrolytic cell in the plurality of electrolytic cells 72 includes various components including a membrane electrode assembly (MEA), a pair of separator plates, and a pair of seals.

[0079] The pair of separator plates (from the plurality of separator plates 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 plate is conductive and facilitates electron transport to help establish an electrical circuit for the electrolysis process.

[0080] 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 in which an electrochemical reaction occurs via electrolysis to convert water into hydrogen. 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.

[0081] Each electrolyzer is structured so that the MEA is disposed between the pair of separator plates. The pair of seals (from the plurality of seals 74) prevents fluid (e.g., water, hydrogen, and oxygen) from leaking from the interface between the MEA and the pair of separator plates. The pair of seals defines the MEA perimeter 79 (at Figure 2 ). The MEA perimeter 79 is the area where the fluid is restricted before exiting the MEA via the pair of separator plates.

[0082] 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 the electrolytic cells, and the perimeter area 76 is associated with the plurality of electrolytic cells 72.

[0083] As illustrated, electrolyzer stack 40 receives water from water source 20 via conduit 22 and receives electrical current from power source 30 via conduit 32. Electrolyzer stack 40 may receive electrical current via wiring, busses, and / or electrical connectors (not shown) that are electrically coupled to terminal block 160 (e.g., a first terminal block), for example.

[0084] Water advances into and through the electrolyzer block 70 via the water inlet 180, which feeds the plurality of electrolyzers 72 via the plurality of separator plates 210. The terminal plates 160 and 170, the plurality of separator plates 210, and each MEA in the plurality of electrolyzers 72 form an electrical circuit that drives the electrolysis process when current is applied to the electrolyzer block 70. When current passes through the plurality of electrolyzers 72 between the terminal plates 160 and 170, water advancing in the electrolyzers 72 is converted into hydrogen and oxygen via the electrolysis process.

[0085] As illustrated, oxygen and any unused, excess and / or byproduct water are removed from the electrolyzer 72 via the water oxygen outlet 200. The water oxygen outlet 200 forwards the removed water to the recirculation flow line 44 which delivers the water back to the water source 20.

[0086] The hydrogen produced in the electrolyzer 72 proceeds to a hydrogen header 190. The hydrogen exits the electrolyzer stack 40 from the hydrogen header 190 to form a hydrogen product stream 122. The hydrogen product stream 122 proceeds through a hydrogen product line 120 which is coupled to the line 42 (at Figure 1 ) fluidly connected.

[0087] As illustrated, a portion of the hydrogen product stream 122 or side stream 132 is fluidly connected to the capsule 80 via the side stream conduit 130. In one or more embodiments of the present disclosure, this portion of the hydrogen product stream 84 is introduced into the capsule 80 and pressurized. In an exemplary embodiment, the capsule 80 is pressurized at the same or substantially the same pressure as the hydrogen product stream 122. For example, the fluid circuit segment between the electrolyzer block 70 and the capsule 80 including the conduits 120 and 130 may be free of any flow restricting valving or device, or alternatively, if any valving or other flow restricting device is included in the conduits 120 and 130, the valving or (multiple) devices are opened at substantially maximum flow during operation of the electrolysis system 10.

[0088] When the bladder 80 is pressurized, the bladder 80 applies a force (e.g., a compressive force or a force in the direction of the electrolyzer block 70) directly or indirectly to a compression plate 90 (e.g., a movable compression plate, such as upward or downward in the illustrated orientation), which facilitates evenly distributing and transferring the force to the electrolyzer block 70. As illustrated, the compression plate 90 is disposed adjacent to and between the bladder 80 and the electrolyzer block 70, and can be moved toward the electrolyzer block 70 in response to the bladder 80 applying the force to transfer the force to the electrolyzer block 70, for example.

[0089] In one or more embodiments of the present disclosure, the force applied by the bladder 80 is represented by the following equation:

[0090] FB=P B xA B , (1)

[0091] Among them, F B is the force exerted by the bladder 80 on the compression plate 90, P B is the pressure of the hydrogen contained in the capsule 80, and A B A is the area of ​​the bladder 80 that is in physical contact with the compression plate 90. B The bladder 80 is defined by an area created by an outer perimeter 82 (as discussed further below) of the bladder 80 that substantially overlaps the perimeter area 76 defined by the plurality of seals 74. B As discussed below, H2 The same or substantially the same.

[0092] In one or more embodiments of the present disclosure, during operation of the electrolyzer stack 40, due to the generation of hydrogen, the pressure inside the electrolyzer block 70 gradually increases internally, causing the electrolyzer block to exert (multiple) forces in (multiple) outward directions. The forces are described by the following equations:

[0093] F H2 =P H2 x A H2 , (2)

[0094] Among them, F H2 represents the total force from the hydrogen pressure, P H2 represents the total hydrogen pressure, and A H2 is the area defined by the perimeter area 76. H2 are the same because all of the electrolyzer cells in the plurality of electrolyzer cells are identical and are operated as Figure 3 The aligned configuration shown in the stack.

[0095] In some embodiments, if an opposing or counteracting force is not otherwise applied to the electrolyzer stack 40 , the electrolyzer stack 40 may expand (ie, increase in height) when the electrolyzer cell 72 experiences the force(s) caused by the increase in hydrogen gas pressure.

[0096] Capsule F B By applying an equivalent F H2 The opposite force to counteract the total force F H2 Because A B Equal to A H2 , and because the bladder pressure 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.

[0097] In some embodiments, the electrolyzer stack 40 includes an electrolyzer block 70, a compression plate 90, a bladder 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 rod 140, a spring 150, a terminal plate 160, a terminal plate 170, the plurality of electrolyzers 72, and a plurality of seals 74.

[0098] As briefly discussed above, the electrolyzer 72 accordingly includes seals 74 that cover each other to define a perimeter region 76 disposed around an active region 78 of the electrolyzer block 70. As used herein, an "active region" is understood to mean a region or area in which an electrochemical reaction occurs via electrolysis to convert water into hydrogen. As illustrated, a capsule 80 covers the active region 78 of the electrolyzer block 70. As used herein, the term "covering" is understood to mean that in one or more orientations of the electrolyzer block 70, the capsule 80 is located above the electrolyzer block 70, while in other orientations, although the capsule 80 may not be located above the electrolyzer block 70, the capsule 80 is directly or indirectly adjacent to the electrolyzer block 70. The capsule 80 has an outer perimeter 82 that substantially overlaps the perimeter region 76 defined by the plurality of seals 74. The outer perimeter 82 is identical to (e.g., aligned with and matches) or substantially identical to the MEA perimeter 79.

[0099] As illustrated, the cell block 70 is disposed adjacent to and between the terminal plates 160 and 170. On a side of the terminal plate 160 opposite the cell block 70, the compression plate 90 is disposed adjacent to and between the terminal plate 160 and the bladder 80. Further and as illustrated, the bladder 80 is disposed adjacent to and between the compression plate 90 and the end plate 100.

[0100] As discussed above, the bladder 80, when pressurized, applies a force to the compression plate 90, which transmits the force to the electrolyzer block 70. In one or more embodiments of the present disclosure, the bladder 80 applies a force over an area of ​​the bladder 80 that is in physical contact with the compression plate 90. The area (i.e., the bladder area) is the portion of the bladder 80 that is within the perimeter region 76 that is in physical contact with the compression plate 90. That is, the bladder area is substantially aligned with and matches an area of ​​the perimeter region 76.

[0101] In an exemplary embodiment, bladder 80 is formed of or otherwise includes an elastomeric material that can expand and contract without significant plastic deformation. Further, in an exemplary embodiment, the elastomeric material is substantially inert to hydrogen, such that the bladder can be exposed to hydrogen for extended periods of time without any substantial degradation of its physical and mechanical properties, including elongation and elastic properties, and is substantially impermeable to hydrogen. Non-limiting examples of elastomeric materials suitable for forming bladder 80 include polymeric materials such as rubber and fiber-reinforced thermoplastic polymers or metals such as stainless steel and aluminum.

[0102] Further, in an exemplary embodiment, the bladder 80 includes accordion-folded walls (e.g., pleated or foldable wall segments). When the bladder 80 is unpressurized or in a collapsed position, the accordion-folded walls overlap each other to form one or more "V" or folded shapes. When the bladder 80 is pressurized, the accordion-folded walls expand, e.g., the foldable wall segments (e.g., (multiple) "V" folded shapes) expand to increase the length of the wall.

[0103] On the side of the electrolyzer block 70 opposite the bladder 80, a terminal plate 170 is disposed adjacent to and between the electrolyzer 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 electrolyzer block 70, thereby driving the electrolysis of water to form the hydrogen product stream 122.

[0104] As illustrated, hydrogen product stream 122 passes through openings or conduits in end plate 110. Hydrogen product stream 122 is formed from hydrogen produced by electrolysis of water. Further and as illustrated, side stream line 130 is in fluid communication with hydrogen product line 120 and bladder 80. In the exemplary embodiment, side stream line 130 is coupled to hydrogen product line 120 and bladder 80 to deliver this portion of hydrogen product stream 84 to bladder 80, as discussed above.

[0105] In the exemplary embodiment, tension rods 140 and springs 150 (i.e., stack springs) are coupled and cooperate to compress electrolyzer block 70 by connecting end plates 100 and 110 together. End plates 100 and 110 are connected together to constrain expansion of electrolyzer stack 40, including constraining expansion of bladder 80 in a direction away from electrolyzer block 70. In the exemplary embodiment, this helps ensure that bladder 80 directs force toward electrolyzer block 70 when pressurized.

[0106] In the exemplary embodiment, tension rod 140 and spring 150 further assist in providing additional force to electrolytic cell stack 70 to ensure that a certain degree of force is always applied to seal 74 and active area 78 despite any pressure fluctuations and / or dimensional changes that may occur in electrolytic cell block 70 during operation and / or startup of electrolysis system 10.

[0107] Figure 4 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 (step 410) water to an electrolyzer stack 40 including an electrolysis cell block 70.

[0108] Method 400 continues by electrolyzing (step 420) water in the electrolyzer block to form a hydrogen product stream. In the exemplary embodiment, bladder 80 is pressurized (step 430) with a portion of hydrogen product stream 84 to apply a force to the electrolyzer block.

[0109] In an exemplary embodiment, the electrolysis system 10 is incorporated into or otherwise used in a vehicle (e.g., a motor vehicle). As used herein, "vehicle" is understood to mean a device configured for transporting people, things, objects, or the like. Non-limiting examples of motor vehicles (e.g., internal combustion engine (ICE) vehicles, electric vehicles, including electric battery vehicles and fuel cell vehicles, or the like) include land vehicles (e.g., cars, trucks, motorcycles, electric bicycles, buses, trains, or the like), air vehicles (e.g., airplanes, helicopters, unmanned aerial vehicles, or the like), water vehicles (e.g., boats, watercraft, or the like), and amphibious vehicles (e.g., hovercraft, or the like).

[0110] 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.

[0111] Any of the dimensions, configurations, etc. discussed herein may be varied as needed or desired from any value or characteristic specifically mentioned herein or shown in the figures for any embodiment.

[0112] 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 (multiple) disclosures. Other embodiments of the present disclosure will be apparent to those skilled in the art in view of the specification and the practice of the various embodiments disclosed herein. For example, some equipment may be constructed and operated differently than described herein, and certain steps of any method may be omitted, performed in an order different from the order specifically mentioned, or in some cases performed simultaneously or in sub-steps. In addition, certain aspects or features of the various embodiments may be changed or modified to produce further embodiments, and the features and aspects of the various embodiments may be added to or substituted for other features or aspects of other embodiments to provide further embodiments.

Claims

1. An electrolyzer stack comprising: an electrolyzer block comprising a plurality of electrolyzers configured to receive and convert water to form a hydrogen product stream; as well as A bladder is configured for fluid communication with the hydrogen product stream and operatively disposed to apply a force to the electrolyzer block when pressurized by a portion of the hydrogen product stream.

2. The electrolyzer stack of claim 1 further comprising a side stream conduit providing fluid communication between the hydrogen product stream and the bladder to advance the portion of the hydrogen product stream to the bladder.

3. The electrolyzer stack of claim 1 further comprising a compression plate disposed between the bladder and the electrolyzer block, wherein: The bladder, when pressurized, applies the force to the compression plate, which transmits the force to the electrolytic cell block.

4. The electrolyzer stack of claim 3, further comprising a first end plate disposed adjacent to the bladder and opposite the compression plate.

5. The electrolyzer stack of claim 4, further comprising a second end plate disposed adjacent to the electrolyzer block on a side opposite to the compression plate, wherein The first end plate and the second end plate are connected together to restrict expansion of the electrolyzer stack, including restricting expansion of the bladder in a direction away from the electrolyzer block.

6. The electrolyzer stack of claim 5, further comprising a tension rod extending between the first end plate and the second end plate and at least partially connecting the first end plate and the second end plate together.

7. The electrolyzer stack of claim 6, further comprising a spring coupled to and cooperating with a tension rod to connect the first end plate and the second end plate together.

8. The electrolyzer stack of claim 5, wherein: The plurality of electrolytic cells respectively include a plurality of seals disposed between the compression plate and the second end plate and overlying one another to define a perimeter region disposed about an active area of ​​the electrolytic cell block.

9. The electrolyser stack according to claim 8, wherein: The bladder covers the active area of ​​the electrolytic cell block.

10. The electrolyser stack of claim 9, wherein: The bladder has an outer perimeter that interfaces with the compression plate and substantially overlaps the perimeter area defined by the plurality of seals.

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