Electrolytic bath

Abstract

The utility model relates to the technical field of water electrolysis hydrogen production, and provides an electrolytic bath which comprises a first end plate, an electrolysis assembly and a second end plate, and the surface of the first end plate is provided with a pure water inlet, an oxygen outlet and a hydrogen outlet; the electrolysis assembly is connected to one side of the first end plate, an oxygen pipeline and a hydrogen pipeline are formed in the electrolysis assembly, and the oxygen pipeline and the hydrogen pipeline are coupled at the bipolar plate in the electrolysis assembly; the inlet end of the oxygen pipeline is communicated with the pure water inlet, and the outlet end of the oxygen pipeline is communicated with the oxygen outlet; two ends of the hydrogen pipeline are respectively communicated with the hydrogen outlets; the second end plate is arranged at the end, away from the first end plate, of the electrolysis assembly, and purging holes are formed in the surface of the second end plate and communicate with the oxygen pipeline and / or the hydrogen pipeline. According to the electrolytic bath provided by the utility model, the purging hole is formed in the surface of the second end plate, so that residual water in the electrolytic bath is finally discharged through the purging hole under the dual driving of gas kinetic energy and gravity.

Description

Technical Field

[0001] This utility model relates to the field of water electrolysis for hydrogen production technology, and in particular to an electrolyzer. Background Technology

[0002] A proton exchange membrane (PEM) water electrolyzer is a highly efficient hydrogen production device, whose core structure consists of multiple vertically stacked electrolysis chambers. Currently, the industry generally adopts a U-shaped fluid distribution design, in which the main inlet and outlet water pipes of the electrolyzer are arranged on the top of the same side of the core, and pure water is supplied to each electrolysis chamber through parallel flow channels.

[0003] However, due to gravity, residual liquid water in the electrolysis chambers at the bottom of the stack is difficult to effectively drain through the top purge airflow. In cold environments, the freezing and expansion of this residual water can cause physical puncture damage to the membrane electrode assembly (MEA), severely impacting the electrolyzer's lifespan and safety. Furthermore, trace amounts of dissolved oxygen and hydrogen in the unremoved liquid water create a localized concentration gradient, forming an electrochemically active interface on the catalyst layer surface. This induces a reverse fuel cell reaction, accelerating the irreversible oxidation and loss of precious metal catalysts (such as platinum), resulting in a continuous decline in electrolysis efficiency.

[0004] In existing technologies, although attempts have been made to improve drainage by optimizing purging pressure and duration, the inherent gravity drainage bottleneck of the U-shaped flow channel has prevented a complete solution to the problem of residual water in the bottom chamber. Therefore, a novel fluid distribution structure is urgently needed to optimize full-layer drainage during shutdown conditions while ensuring electrolysis efficiency. Utility Model Content

[0005] This invention provides an electrolytic cell to solve the defect of residual water in the bottom chamber in the prior art. By setting a purge hole on the surface of the second end plate, opening the purge hole of the second end plate and introducing purge gas (such as nitrogen), the residual water in the electrolytic cell can migrate directionally along the path of first end plate → electrolytic component → second end plate under the dual drive of gas kinetic energy and gravity, and finally be discharged through the purge hole.

[0006] The electrolytic cell provided by this utility model includes:

[0007] The first end plate has a pure water inlet, an oxygen outlet, and a hydrogen outlet on its surface.

[0008] An electrolysis assembly is connected to one side of the first end plate. An oxygen pipe and a hydrogen pipe are formed inside the electrolysis assembly. The oxygen pipe and the hydrogen pipe are coupled at the bipolar plate inside the electrolysis assembly. The inlet end of the oxygen pipe is connected to the pure water inlet, and the outlet end of the oxygen pipe is connected to the oxygen outlet. The two ends of the hydrogen pipe are respectively connected to the hydrogen outlet.

[0009] The second end plate is located at the end of the electrolysis assembly away from the first end plate. The surface of the second end plate is provided with a purge hole, which is connected to the oxygen pipeline and / or hydrogen pipeline.

[0010] According to the electrolytic cell provided by this utility model, the purging hole includes an anode purging hole and a cathode purging hole. The anode purging hole is connected to the oxygen pipeline, and the cathode purging hole is connected to the hydrogen pipeline.

[0011] According to the electrolytic cell provided by this utility model, a plurality of anode purging holes are provided, and the plurality of anode purging holes are evenly spaced on the side wall of the second end plate.

[0012] According to the electrolytic cell provided by this utility model, the anode purging hole and the oxygen pipeline are located on the same side.

[0013] According to the electrolytic cell provided by this utility model, a plurality of anode purging holes are provided, and the plurality of anode purging holes are evenly spaced on the bottom wall of the second end plate.

[0014] According to the electrolytic cell provided by this utility model, a plurality of cathode purging holes are provided, and the plurality of cathode purging holes are evenly spaced on the side wall of the second end plate.

[0015] According to the electrolytic cell provided by this utility model, the cathode purging hole and the hydrogen pipeline are located on the same side.

[0016] According to the electrolytic cell provided by this utility model, a plurality of cathode purging holes are provided, and the plurality of cathode purging holes are evenly spaced on the bottom wall of the second end plate.

[0017] The electrolytic cell provided by this utility model also includes a sealing plug, the shape of which matches the shape of the purge hole, and the sealing plug is used to block the purge hole.

[0018] The electrolytic cell provided by this utility model also includes a water inlet tank, which is formed on the surface of the second end plate. The anode purge hole and the cathode purge hole are respectively connected to the water inlet tank. The water inlet tank is used to collect the water flowing out of the anode purge hole and the cathode purge hole and discharge it.

[0019] In the electrolytic cell provided by this invention, a purge hole is provided on the surface of the second end plate. When the electrolytic cell is shut down, the purge hole on the second end plate is opened and a purge gas (such as nitrogen) is introduced. Driven by both the kinetic energy of the gas and gravity, the residual water in the electrolytic cell can migrate directionally along the path from the first end plate to the electrolytic assembly and then to the second end plate, and is finally discharged through the purge hole. Compared to traditional top-side purge, this design significantly improves the drainage efficiency of the bottom area, reduces the risk of ice formation and rupture of the membrane electrode in cold environments, and solves the problem that the storage temperature needs to be above 5°C when the electrolytic cell is shut down.

[0020] In addition, by forcibly removing residual water containing trace amounts of dissolved oxygen and hydrogen through the purge holes, the electrolyte environment required for the reverse fuel cell reaction can be disrupted, preventing the formation of effective electrochemical active sites on the catalyst layer surface, which can significantly extend the life of the electrolyzer. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the axial structure of the electrolytic cell provided by this utility model.

[0023] Figure 2 This is a schematic diagram of the oxygen pipeline of the electrolytic cell provided by this utility model.

[0024] Figure 3 This is a schematic diagram of the hydrogen pipeline of the electrolytic cell provided by this utility model.

[0025] Figure 4 This is a schematic diagram of the anode side purging provided by this utility model.

[0026] Figure 5 This is a schematic diagram of the cathode side purging provided by this utility model.

[0027] Figure 6 This is an axial side view of the second end plate provided in an embodiment of the present invention.

[0028] Figure label:

[0029] 10: First end plate; 20: Electrolysis assembly; 21: Oxygen pipeline; 22: Hydrogen pipeline; 30: Second end plate; 40: Purge hole; 41: Anode purge hole; 42: Cathode purge hole; 50: Pure water main pipe; 51: Oxygen main pipe; 52: Hydrogen main pipe; 53: Negative electrode insulating plate; 54: Negative electrode current collector; 55: Electrolytic cell circulation chamber; 56: Positive electrode current collector; 57: Positive electrode insulating plate. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0032] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0034] Figure 1 This is a schematic diagram of the axial structure of the electrolytic cell provided by this utility model; Figure 2 This is a schematic diagram of the oxygen pipeline of the electrolytic cell provided by this utility model; Figure 3 This is a schematic diagram of the hydrogen pipeline of the electrolytic cell provided by this utility model.

[0035] See Figures 1 to 3 This utility model embodiment provides an electrolytic cell. The basic structure of the electrolytic cell is briefly described below. The electrolytic cell includes a first end plate 10, an electrolysis component 20, and a second end plate 30. In addition, the electrolytic cell also includes a pure water main pipe 50, an oxygen main pipe 51, and a hydrogen main pipe 52.

[0036] Specifically, the first end plate 10 and the second end plate 30 are arranged opposite to each other. The specific structure of the first end plate 10 can be referred to the negative end plate in the prior art, and the specific structure of the second end plate 30 can be referred to the positive end plate in the prior art. The surface of the first end plate 10 is formed with a pure water inlet, an oxygen outlet and a hydrogen outlet. The pure water inlet is connected to the pure water main pipe 50, which is used to transport pure water to the electrolyzer.

[0037] An oxygen outlet is connected to an oxygen main pipe 51, which receives water and oxygen flowing out of the oxygen outlet. A hydrogen main pipe 52 is connected to a hydrogen outlet, which receives water and hydrogen flowing out of the hydrogen outlet. The first end plate 10 provided in this embodiment of the invention has two hydrogen outlets, which are positioned opposite each other on the side wall of the first end plate 10 (specifically...). Figure 1 The specific number and location of hydrogen outlets (as shown in the front and rear of the first end plate 10) can be adapted to actual needs. For example, only one hydrogen outlet can be set.

[0038] The electrolysis assembly 20 is disposed between the first end plate 10 and the second end plate 30. The three are connected as a whole by fasteners such as bolts. For the specific structure, please refer to the existing technology adaptation design. The electrolysis assembly 20 includes a negative electrode insulating plate 53, a negative electrode current collector 54, an electrolytic cell circulation chamber 55, a positive electrode current collector 56, and a positive electrode insulating plate 57, etc. Among them, the electrolytic cell circulation chamber 55 integrates a bipolar plate.

[0039] like Figure 1 As shown, the second end plate 30 is located at the bottom of the electrolytic cell. The positive electrode insulating plate 57 is arranged on the second end plate 30, the positive electrode current collector 56 is arranged on the positive electrode insulating plate 57, the electrolytic cell circulation chamber 55 is arranged on the positive electrode current collector 56, the negative electrode current collector 54 is arranged on the electrolytic cell circulation chamber 55, the negative electrode insulating plate 53 is arranged on the negative electrode current collector 54, and the first end plate 10 is arranged on the negative electrode insulating plate 53. The specific structure and function of the electrolysis assembly 20 can be found in the prior art, and will not be described in detail here.

[0040] The electrolytic cell circulation chamber 55 contains an isolated oxygen pipe 21 and a hydrogen pipe 22. The oxygen pipe 21 is coupled at the bipolar plate. The inlet end of the oxygen pipe 21 is connected to the pure water inlet, and the outlet end of the oxygen pipe 21 is connected to the oxygen outlet. The two ends of the hydrogen pipe 22 are respectively connected to the two hydrogen outlets mentioned above.

[0041] See Figures 1 to 3 The working principle of the electrolyzer is shown below: During the operation of the electrolyzer, pure water flows into the electrolyzer from the pure water main pipe 50, passes through the first end plate 10, the negative electrode insulating plate 53, and the negative electrode current collector 54, and then enters the electrolyzer circulation chamber 55. An electrochemical reaction occurs at the membrane electrode to generate hydrogen and oxygen. Water and oxygen flow out of the electrolyzer through the oxygen main pipe 51, and hydrogen flows out of the electrolyzer through the hydrogen main pipe 52.

[0042] Figure 4 This is a schematic diagram of the anode side purging provided by this utility model; Figure 5 This is a schematic diagram of the cathode side purging provided by this utility model.

[0043] See Figure 4 and Figure 5 The surface of the second end plate 30 is provided with a purge hole 40, which is connected to the oxygen pipeline 21; in some other optional embodiments, the purge hole 40 is connected to the hydrogen pipeline 22; during the shutdown and purging process of the electrolytic cell, the purge hole 40 on the second end plate 30 can be opened. Under the purging of nitrogen, some of the water remaining in the circulation chamber 55 of the electrolytic cell reaches the second end plate 30 through the positive current collector 56 and the positive insulating plate 57. The remaining water can be discharged from the electrolytic cell through the purge hole 40 under the combined action of wind and gravity.

[0044] See Figure 4and Figure 5 It is understood that in the electrolytic cell provided in this embodiment of the present invention, by providing a purge hole 40 on the surface of the second end plate 30, when the electrolytic cell is shut down, the purge hole 40 of the second end plate 30 is opened and a purge gas (such as nitrogen) is introduced. Under the dual drive of gas kinetic energy and gravity, the residual water in the electrolytic cell can migrate directionally along the path of the first end plate 10 → electrolytic component 20 → second end plate 30, and finally be discharged through the purge hole 40. Compared with the traditional top-side purge, this design can significantly improve the drainage efficiency of the bottom area, reduce the risk of ice formation and rupture of the membrane electrode in cold environments, and solve the problem that the storage temperature needs to be higher than 5°C when the electrolytic cell is shut down.

[0045] In addition, by forcibly removing residual water containing trace amounts of dissolved oxygen and hydrogen through the purge port 40, the electrolyte environment required for the reverse fuel cell reaction can be disrupted, preventing the formation of effective electrochemical active sites on the catalyst layer surface, which can significantly extend the life of the electrolyzer.

[0046] Continue reading Figure 4 and Figure 5 In an optional embodiment of this utility model, the purge port 40 includes an anode purge port 41 and a cathode purge port 42. The anode purge port 41 is connected to the oxygen pipeline 21, and the cathode purge port 42 is connected to the hydrogen pipeline 22. It is understood that such a distinguishing structure is beneficial to integrate the purge port 40 into the pipeline within the electrolysis assembly 20. This eliminates the limitation on the design and manufacturing of the purge port 40 caused by the isolation of the oxygen pipeline 21 and the hydrogen pipeline 22, thereby improving the design flexibility of the purge port 40 and reducing the design difficulty.

[0047] Furthermore, based on this design, the purging mode can be flexibly selected according to different shutdown scenarios (such as emergency power outages and planned maintenance). For example, prioritizing the purging of oxygen pipeline 21 can specifically remove the oxygen-rich residual water after the electrolysis reaction, further reducing the risk of oxidation and corrosion.

[0048] Figure 6 This is an axial side view of the second end plate provided in an embodiment of the present invention.

[0049] See Figure 6In an optional embodiment of this invention, multiple anode purging holes 41 are provided, and these multiple anode purging holes 41 are evenly spaced on the sidewall of the second end plate 30. It is understood that the evenly spaced multiple purging holes 40 can cover multiple locations at the bottom of the electrolytic cell, eliminating local dead zones in the flow field caused by single-hole purging. Furthermore, the porous layout effectively shortens the gravity-driven migration path of residual water at the bottom of the electrolytic component 20. Moreover, the porous layout allows for a larger gas flow rate per unit time, meaning a faster gas flow velocity within the electrolytic component 20. This allows the gas flow to carry more residual water per unit time, effectively reducing the purging time required.

[0050] Secondly, the purge hole 40 is set on the side wall of the second end plate 30. This structure is conducive to the setting of the exhaust structure and the external drainage structure. The external drainage pipe or exhaust pipe does not need to bend or detour, which can effectively improve the convenience of using the electrolytic cell.

[0051] Continue reading Figure 6 In an optional embodiment of this utility model, the anode purge hole 41 and the oxygen pipeline are located on the same side. This arrangement facilitates the processing and design of the anode purge hole 41 and effectively reduces the manufacturing difficulty of the second end plate 30. During installation, compared with the opposite side arrangement, this design reduces the clamping and positioning required by the traditional opposite side layout, thus reducing assembly time. Furthermore, the fact that the anode purge hole 41 and the oxygen pipeline are located on the same side reduces the total migration path of residual water, thereby reducing purging resistance and improving purging efficiency.

[0052] In an optional embodiment of this utility model, multiple anode purge holes 41 are provided, and the multiple anode purge holes 41 are evenly spaced on the bottom wall of the second end plate 30. With this arrangement, residual water flows naturally into the purge holes 40 through the shortest vertical path driven by gravitational potential energy, which can effectively improve the drainage speed compared to the side wall hole design.

[0053] See Figure 6 In an optional embodiment of this invention, multiple cathode purging holes 42 are provided, and these holes 42 are evenly spaced on the sidewall of the second end plate 30. It is understood that the evenly spaced multiple cathode purging holes 42 can cover multiple locations at the bottom of the electrolytic cell, eliminating local dead zones caused by single-hole purging. Furthermore, the porous layout effectively shortens the gravity-driven migration path of residual water at the bottom of the electrolytic component 20. Moreover, the porous layout allows for a larger gas flow rate per unit time, meaning a faster gas flow velocity within the electrolytic component 20. This allows the gas flow to carry more residual water per unit time, effectively reducing the purging time required.

[0054] Secondly, the purge hole 40 is set on the side wall of the second end plate 30. This structure is conducive to the setting of the exhaust structure and the external drainage structure. For example, the external drainage pipe or exhaust pipe does not need to bend or detour, which can effectively improve the convenience of using the electrolytic cell.

[0055] Continue reading Figure 6 In an optional embodiment of this utility model, the cathode purge hole 42 and the hydrogen pipeline are located on the same side. This arrangement facilitates the processing and design of the cathode purge hole 42 and effectively reduces the manufacturing difficulty of the second end plate 30. During installation, compared with the opposite side arrangement, this design can reduce the clamping and positioning required by the traditional opposite side layout and reduce assembly time. Furthermore, the fact that the cathode purge hole 42 and the hydrogen pipeline are located on the same side can reduce the total migration path of residual water, thereby reducing purging resistance and improving purging efficiency.

[0056] In an optional embodiment of this utility model, multiple cathode purge holes 42 are provided, and the multiple cathode purge holes 42 are evenly spaced on the bottom wall of the second end plate 30. With this arrangement, residual water flows naturally into the purge holes 40 through the shortest vertical path driven by gravitational potential energy, which can effectively improve the drainage speed compared to the side wall hole design.

[0057] In an optional embodiment of this utility model, the electrolytic cell further includes a sealing plug, the shape of which matches the shape of the purge hole 40. The sealing plug is used to seal the purge hole 40. For example, the two can be connected by a threaded fit. The sealing plug can be adapted to existing technologies. When the electrolytic cell is working, the sealing plug can ensure the sealing of the internal oxygen pipe 21 and hydrogen pipe 22.

[0058] In an optional embodiment of this invention, the electrolytic cell further includes a water inlet tank, which is formed on the surface of the second end plate 30. The anode purge hole 41 and the cathode purge hole 42 are respectively connected to the water inlet tank. The water inlet tank is used to collect the water flowing out from the anode purge hole 41 and the cathode purge hole 42 and discharge it. It is understood that this design can reduce the number of external drainage pipes, reduce the difficulty of laying external pipes, and reduce the overall manufacturing cost of the electrolytic cell.

[0059] It should be noted that the technical solutions in the various embodiments of this utility model can be combined with each other, but the basis for such combination is that they can be implemented by those skilled in the art. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist, that is, it is not within the protection scope of this utility model.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. An electrolytic cell, characterized in that, include: The first end plate has a pure water inlet, an oxygen outlet, and a hydrogen outlet on its surface. An electrolysis assembly is connected to one side of the first end plate. An oxygen pipe and a hydrogen pipe are formed inside the electrolysis assembly. The oxygen pipe and the hydrogen pipe are coupled at the bipolar plate inside the electrolysis assembly. The inlet end of the oxygen pipe is connected to the pure water inlet, and the outlet end of the oxygen pipe is connected to the oxygen outlet. The two ends of the hydrogen pipe are respectively connected to the hydrogen outlet. The second end plate is located at the end of the electrolysis assembly away from the first end plate. The surface of the second end plate is provided with a purge hole, which is connected to the oxygen pipeline and / or hydrogen pipeline.

2. The electrolytic cell according to claim 1, characterized in that, The purge port includes an anode purge port and a cathode purge port. The anode purge port is connected to the oxygen pipeline, and the cathode purge port is connected to the hydrogen pipeline.

3. The electrolytic cell according to claim 2, characterized in that, The anode purging holes are provided in multiple locations, and the multiple anode purging holes are evenly spaced on the side wall of the second end plate.

4. The electrolytic cell according to claim 3, characterized in that, The anode purge port and the oxygen pipeline are located on the same side.

5. The electrolytic cell according to claim 2, characterized in that, The anode purging holes are provided in multiple locations, and the multiple anode purging holes are evenly spaced on the bottom wall of the second end plate.

6. The electrolytic cell according to claim 2, characterized in that, The cathode purging holes are provided in multiple ways, and the multiple cathode purging holes are evenly spaced on the side wall of the second end plate.

7. The electrolytic cell according to claim 5, characterized in that, The cathode purge port and the hydrogen pipeline are located on the same side.

8. The electrolytic cell according to claim 2, characterized in that, The cathode purging holes are provided in multiple ways, and the multiple cathode purging holes are evenly spaced on the bottom wall of the second end plate.

9. The electrolytic cell according to any one of claims 1 to 8, characterized in that, It also includes a sealing plug, the shape of which matches the shape of the purge hole, the sealing plug being used to seal the purge hole.

10. The electrolytic cell according to any one of claims 2 to 8, characterized in that, It also includes a water inlet channel, which is formed on the surface of the second end plate. The anode purge hole and the cathode purge hole are respectively connected to the water inlet channel. The water inlet channel is used to collect the water flowing out of the anode purge hole and the cathode purge hole and discharge it.

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