Square under-pressure alkaline electrolytic cell

Abstract

The invention discloses a square under-pressure alkaline electrolytic bath, which relates to the technical field of water electrolysis hydrogen production, and comprises a left end plate, an electrolytic bath main body and a right end plate which are fixedly connected, the electrolytic cell main body comprises a plurality of stacked small electrolytic chambers; the small electrolysis chamber comprises a square bipolar plate, the square bipolar plate is provided with an installation process hole and an inlet and outlet for alkali liquor circulation, grooves are formed in the two sides of the square bipolar plate respectively, metal supporting nets are fixed in the grooves, and a cathode electrode and an anode electrode are fixed to the metal supporting nets on the two sides of the square bipolar plate respectively. And a diaphragm is arranged between the cathode electrode and the anode electrode. By arranging the metal supporting net, the effective contact area between the square bipolar plate and the electrode is increased, the ohmic impedance of the electrolytic cell is reduced, and then the hydrogen production efficiency is improved; and the metal supporting net also enables the flow field distribution to be more uniform, so that the accumulation phenomenon of gas in the electrolytic cell is effectively improved, and the operation stability is improved.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production by electrolyzing water, and particularly to a square pressurized alkaline electrolyzer. Background Art

[0002] The electrolyzer is the most core component of the alkaline electrolytic water hydrogen production system. At present, there are mainly two mainstream technical routes in China: circular pressurized and square atmospheric pressure. Important components such as electrodes and diaphragms of the circular pressurized electrolyzer will cause material waste during the cutting process, increasing production costs. Moreover, the current density of the circular alkaline electrolyzer generally does not exceed 4000 A / m 2 during normal operation, and the hydrogen production efficiency is relatively low; while the square atmospheric pressure electrolyzer can avoid material waste of electrodes and diaphragms, and the current density can reach 8000 - 10000 A / m 2 during normal operation, but its pressure resistance performance is poor. In terminal high-pressure application scenarios or hydrogen storage, additional compression equipment is required to boost the prepared hydrogen, resulting in certain limitations in the application scenarios and being not conducive to reducing the energy consumption of the alkaline electrolytic water hydrogen production system. Therefore, how to design a square pressurized alkaline electrolyzer that can combine the advantages of both has become a problem that needs to be studied.

[0003] In the prior art, Chinese Patent CN116445942A discloses a square electrolyzer, including: an anode plate, a cathode plate, and a diaphragm; the diaphragm is located between the anode plate and the cathode plate; the diaphragm and the anode plate are attached together to form an anode flow channel, and the diaphragm and the cathode plate are attached together to form a cathode flow channel; the anode flow channel includes an anode main flow channel and an anode pre-distribution cavity. An anode alkaline liquid inlet and an anode alkaline liquid outlet are provided on the anode plate. The anode pre-distribution cavity is located between the anode main flow channel and the anode alkaline liquid inlet, and the anode main flow channel is located between the anode pre-distribution cavity and the anode alkaline liquid outlet; an anode electrode is provided in the anode flow channel; the cathode flow channel includes a cathode main flow channel and a cathode pre-distribution cavity. A cathode alkaline liquid inlet and a cathode alkaline liquid outlet are provided on the cathode plate. The cathode pre-distribution cavity is located between the cathode main flow channel and the cathode alkaline liquid inlet, and the cathode main flow channel is located between the cathode pre-distribution cavity and the cathode alkaline liquid outlet; a cathode electrode is provided in the cathode flow channel.

[0004] The lower the ohmic impedance of the electrolyzer, the higher the current density during normal operation, and thus the higher the hydrogen production efficiency. However, the above prior art does not consider how to reduce the ohmic impedance of the electrolyzer, and the hydrogen production efficiency is low; in addition, the above prior art does not study the accumulation phenomenon of gas inside the electrolyzer, and the operation stability is poor. Summary of the Invention

[0005] The present application provides a square pressurized alkaline electrolyzer to solve the problems in the prior art that it does not consider how to reduce the ohmic impedance of the electrolyzer, the hydrogen production efficiency is relatively low, it does not study the accumulation phenomenon of gas inside the electrolyzer, and the operation stability is relatively poor.

[0006] On the one hand, the present application provides a square pressurized alkaline electrolyzer, including: a left end plate, an electrolyzer main body, and a right end plate that are fixedly connected.

[0007] The electrolyzer main body includes a plurality of stacked electrolysis chambers.

[0008] The electrolysis chamber includes: a square bipolar plate, the square bipolar plate is provided with installation process holes and inlets and outlets for the circulation of alkaline liquid, grooves are respectively arranged on both sides of the square bipolar plate, a metal support mesh is fixed in the grooves, a cathode electrode and an anode electrode are respectively fixed on the metal support meshes on both sides of the square bipolar plate, the cathode electrode and the corresponding metal support mesh together form a cathode flow channel, the anode electrode and the corresponding metal support mesh together form an anode flow channel, and a diaphragm is arranged between the cathode electrode and the anode electrode.

[0009] In a possible implementation manner, an intermediate plate is arranged at the middle position of the electrolyzer main body, grooves are respectively arranged on both sides of the intermediate plate, a metal support mesh is fixed in the grooves, anode electrodes are respectively fixed on the metal support meshes on both sides of the intermediate plate, the anode electrodes and the corresponding metal support mesh together form an anode flow channel, and the intermediate plate and the square bipolar plates adjacent to its two sides form an electrolysis chamber.

[0010] In a possible implementation manner, the intermediate plate is provided with a positive power supply terminal, and the left end plate and the right end plate are both provided with negative power supply terminals.

[0011] The left end plate and the right end plate are respectively provided with an alkaline liquid inlet and an alkaline liquid outlet, and are both provided with installation process holes and tension bolt holes. Grooves are arranged on the sides of the left end plate and the right end plate adjacent to the electrolyzer main body, a metal support mesh is fixed in the grooves, cathode electrodes are respectively fixed on the metal support meshes of the left end plate and the right end plate, and the cathode electrodes and the corresponding metal support mesh together form a cathode flow channel. The left end plate and the square bipolar plate adjacent to its right side form an electrolysis chamber, and the right end plate and the square bipolar plate adjacent to its left side form an electrolysis chamber.

[0012] In a possible implementation manner, inter-board insulating pads are arranged between adjacent square bipolar plates, between the left end plate and the electrolyzer main body, between the electrolyzer main body and the right end plate, and between the intermediate plate and the square bipolar plates on both sides.

[0013] The inter-board insulating pad is provided with installation process holes and flow channels for the passage of alkaline liquid.

[0014] In a possible implementation, the insulating gasket between the plates is made of polyether ether ketone material.

[0015] In a possible implementation, sealing grooves are provided on both sides of the square bipolar plate, on the side of the left end plate facing the electrolytic cell body, on the side of the right end plate facing the electrolytic cell body, and on both sides of the intermediate plate.

[0016] An O-ring seal is placed in the sealing groove. The O-ring seal is in an O shape initially and is adapted to the shape of the sealing groove during installation.

[0017] In a possible implementation, the O-ring seal is made of ethylene propylene diene monomer material.

[0018] In a possible implementation, bases are provided below the left end plate and the right end plate.

[0019] In a possible implementation, the left end plate, the electrolytic cell body, and the right end plate are fixedly connected by a fastening device.

[0020] The fastening device includes: a tension bolt, a backup nut, a nut, a guide sleeve, a disc spring, a fixing ring, an insulating gasket, and an insulating sleeve.

[0021] A square pressurized alkaline electrolytic cell in the present application has the following advantages:

[0022] By providing a metal support mesh, the effective contact area between the square bipolar plate and the electrode is increased, the ohmic impedance of the electrolytic cell is reduced, and thus the hydrogen production efficiency is improved; the metal support mesh also makes the flow field distribution more uniform, effectively improves the gas accumulation phenomenon inside the electrolytic cell, and improves the operation stability.

[0023] An intermediate plate is provided at the middle position of the proposed electrolytic cell body. The intermediate plate is provided with a power positive terminal, and both the left end plate and the right end plate are provided with power negative terminals, so that the electrolytic cell forms a wiring mode of one positive and two negatives, making the current distribution in the electrolytic cell more uniform and improving the electrolysis efficiency.

[0024] The insulating gasket between the plates proposed is made of polyether ether ketone material, which improves the mechanical strength, heat resistance, and alkali resistance, and can be reused.

[0025] The proposed O-ring is made of ethylene propylene diene monomer (EPDM) material. Compared with the traditional polytetrafluoroethylene material that requires customizing the seal ring shape, the O-ring made of EPDM material is initially in an O shape, with lower processing difficulty. It only needs to be deformed into the shape of the corresponding groove during installation and can be reused. At the same time, it is suitable for alkaline, hydrogen oxygen, and high and low temperature environments and has good gas impermeability.

[0026] The O-ring in this application has self-sealing performance under pressurized conditions, improving the sealing and pressure resistance performance of the electrolyzer. Under pressurized conditions inside the square electrolyzer, it has a compression effect on the gas generated by electrolysis, reducing the volume of bubbles, promoting the escape of gas with the alkali solution from the electrolyzer, reducing the solution resistance, and at the same time preventing large-area attachment of bubbles on the electrode surface, which is beneficial to reducing the activation overpotential, thereby further improving the hydrogen production efficiency of the electrolyzer. And the hydrogen generated in the square pressurized alkaline electrolyzer in this application has a relatively high pressure, reducing the need for secondary pressurization, broadening the application scenarios, and being able to flexibly adapt to different working environments. Especially in high-pressure application scenarios, it saves the cost expenditure of hydrogen compression equipment and the working energy consumption of hydrogen compression equipment, and can reduce the energy consumption of the entire electrolytic hydrogen production system.

[0027] The O-ring in this application only requires one-time cold drawing during assembly, and installation and replacement are also very easy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic structural diagram of the electrolyzer main body provided by the embodiment of the present application;

[0030] Figure 2 It is a schematic overall structural diagram of a square pressurized alkaline electrolyzer provided by the embodiment of the present application;

[0031] Figure 3 It is a schematic structural diagram of the fastening device provided by the embodiment of the present application;

[0032] Figure 4 It is a schematic structural diagram of the sealing groove provided by the embodiment of the present application.

[0033] Description of the reference numerals:

[0034] 1 - Left end plate, 3 - Right end plate, 211 - Square bipolar plate, 212 - Metal support mesh, 213 - Cathode electrode, 214 - Anode electrode, 22 - Diaphragm, 23 - Insulating gasket between plates, 24 - Intermediate plate, 4 - Fastening device, 5 - Base, 6 - Positive power supply terminal, 7 - Negative power supply terminal, 41 - Tension bolt, 42 - Backup nut, 43 - Nut, 44 - Guide sleeve, 45 - Disc spring, 46 - Fixed ring, 47 - Insulating gasket, 48 - Insulating sleeve, 215 - Sealing groove. Detailed implementation mode

[0035] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0036] As Figure 1 and Figure 2 shown, the embodiment of the present application provides a square pressurized alkaline electrolyzer, including: a left end plate 1, an electrolyzer main body, and a right end plate 3 that are fixedly connected.

[0037] The electrolyzer main body includes a plurality of stacked electrolysis chambers.

[0038] Each electrolysis chamber includes: a square bipolar plate 211, the square bipolar plate 211 is provided with installation process holes and inlets and outlets for the circulation of alkaline liquid, grooves are respectively arranged on both sides of the square bipolar plate 211, a metal support mesh 212 is fixed in the grooves, a cathode electrode 213 and an anode electrode 214 are respectively fixed on the metal support meshes 212 on both sides of the square bipolar plate 211, the cathode electrode 213 and the corresponding metal support mesh 212 together form a cathode flow channel, the anode electrode 214 and the corresponding metal support mesh 212 together form an anode flow channel, and a diaphragm 22 is arranged between the cathode electrode 213 and the anode electrode 214.

[0039] Specifically, the diaphragm 22 is provided to separate the cathode electrode 213 and the anode electrode 214 between adjacent electrolysis chambers to prevent the mixing of hydrogen and oxygen.

[0040] Specifically, during the assembly process of the electrolyzer, the tooling positions of each component are fixed through the installation process holes. During the operation process of the electrolyzer, the inlets and outlets for the circulation of alkaline liquid on the square bipolar plate 211 distribute the alkaline liquid to each electrolysis chamber.

[0041] Exemplarily, an intermediate plate 24 is provided at the middle position of the electrolytic cell body. Grooves are respectively provided on both sides of the intermediate plate 24, and a metal support mesh 212 is fixed in the grooves. Anode electrodes 214 are respectively fixed to the metal support meshes 212 on both sides of the intermediate plate 24. The anode electrode 214 and the corresponding metal support mesh 212 together form an anode flow channel. The intermediate plate 24 and the square bipolar plates 211 adjacent to its both sides form an electrolytic chamber.

[0042] Exemplarily, the intermediate plate 24 is provided with a positive power supply terminal 6, and the left end plate 1 and the right end plate 3 are both provided with negative power supply terminals 7.

[0043] The left end plate 1 and the right end plate 3 are respectively provided with an alkali liquid inlet and an alkali liquid outlet, and both are provided with installation process holes and tension bolt holes. Grooves are provided on the sides of the left end plate 1 and the right end plate 3 adjacent to the electrolytic cell body, and a metal support mesh 212 is fixed in the grooves. Cathode electrodes 213 are respectively fixed to the metal support meshes 212 of the left end plate 1 and the right end plate 3. The cathode electrode 213 and the corresponding metal support mesh 212 together form a cathode flow channel. The left end plate 1 and the square bipolar plate 211 adjacent to its right side form an electrolytic chamber, and the right end plate 3 and the square bipolar plate 211 adjacent to its left side form an electrolytic chamber.

[0044] Specifically, through the setting of the intermediate plate 24, the positive power supply terminal 6, and the negative power supply terminals 7, the electrolytic cell forms a wiring method of one positive and two negatives, making the current distribution in the electrolytic cell more uniform and improving the electrolysis efficiency. All the electrolytic chambers are in a series structure.

[0045] Specifically, the alkali liquid flows into the interior of the electrolytic cell body from the alkali liquid inlet. After an electrochemical reaction occurs, the generated gas flows out with the alkali liquid from the alkali liquid outlet.

[0046] Exemplarily, inter - plate insulating pads 23 are provided between adjacent square bipolar plates 211, between the left end plate 1 and the electrolytic cell body, between the electrolytic cell body and the right end plate 3, and between the intermediate plate 24 and the square bipolar plates 211 on both sides.

[0047] The inter - plate insulating pad 23 is provided with installation process holes and flow channels for the alkali liquid to pass through.

[0048] Specifically, the setting of the inter - plate insulating pad 23 is to ensure insulation and sealing between the left end plate 1, the square bipolar plates 211, the intermediate plate 24, and the electrode frames of the right end plate 3.

[0049] Exemplarily, the inter - plate insulating pad 23 is made of polyether ether ketone material.

[0050] Such as Figure 4As shown, exemplarily, sealing grooves 215 are provided on both sides of the square bipolar plate 211, on the side of the left end plate 1 facing the electrolytic cell body, on the side of the right end plate 3 facing the electrolytic cell body, and on both sides of the intermediate plate 24.

[0051] An O-ring seal is placed in the sealing groove 215. The O-ring seal is O-shaped initially and is adapted to the shape of the sealing groove 215 during installation.

[0052] Specifically, the sealing grooves 215 are distributed around the cathode flow channels and anode flow channels of each electrolytic sub-chamber, and the shape is close to the outer contour of the flow channels, further enhancing the sealing effect.

[0053] Exemplarily, the O-ring seal is made of ethylene propylene diene monomer (EPDM) material.

[0054] Exemplarily, bases 5 are provided below the left end plate 1 and the right end plate 3.

[0055] Specifically, the base 5 is used to support the entire electrolytic cell.

[0056] As Figure 2 and Figure 3 shown, exemplarily, the left end plate 1, the electrolytic cell body, and the right end plate 3 are fixedly connected by a fastening device 4.

[0057] The fastening device 4 includes: a tension bolt 41, a backup nut 42, a nut 43, a guide sleeve 44, a disc spring 45, a fixing ring 46, an insulating gasket 47, and an insulating sleeve 48.

[0058] Specifically, in this embodiment, the left end plate 1, the electrolytic cell body, and the right end plate 3 are tightened and fixed through the fastening device 4 in combination with the tension bolt holes of the left end plate 1 and the right end plate 3.

[0059] In the embodiment of the present application, by providing the metal support mesh 212, the effective contact area between the square bipolar plate 211 and the electrodes is increased, the ohmic impedance of the electrolytic cell is reduced, and thus the hydrogen production efficiency is improved; the metal support mesh 212 also makes the flow field distribution more uniform, effectively improves the gas accumulation phenomenon inside the electrolytic cell, and improves the operation stability.

[0060] An intermediate plate 24 is provided at the middle position of the proposed electrolytic cell body. The intermediate plate 24 is provided with a power supply positive terminal 6, and the left end plate 1 and the right end plate 3 are both provided with power supply negative terminals 7, so that the electrolytic cell forms a wiring method of one positive and two negatives, making the current distribution in the electrolytic cell more uniform and improving the electrolysis efficiency.

[0061] The proposed insulating gasket 23 between plates is made of polyether ether ketone material, which improves mechanical strength, heat resistance and alkali resistance, and can be reused.

[0062] The proposed O-ring seal is made of ethylene propylene diene monomer (EPDM) material. Compared with the traditional polytetrafluoroethylene material that requires special customization of the seal ring shape, the O-ring seal made of EPDM material is in the shape of an O-ring initially, with lower processing difficulty. It only needs to be deformed into the shape of the corresponding groove during installation and can be reused. At the same time, it is suitable for alkaline, hydrogen oxygen and high and low temperature environments and has good gas impermeability.

[0063] The O-ring seal in this application has self-sealing performance under pressurized conditions, which improves the sealing and pressure resistance performance of the electrolytic cell. Under pressurized conditions inside the square electrolytic cell, it has a compression effect on the gas generated by electrolysis, reducing the volume of bubbles, promoting the escape of gas with the alkali solution from the electrolytic cell, reducing the solution resistance, and at the same time preventing bubbles from adhering to the electrode surface on a large area, which is beneficial to reducing the activation overpotential, thereby further improving the hydrogen production efficiency of the electrolytic cell. And the hydrogen generated in the square pressurized alkaline electrolytic cell in this application has a relatively high pressure, reducing the need for secondary pressurization, broadening the application scenarios, and being able to flexibly adapt to different working environments. Especially in high-pressure application scenarios, it saves the cost expenditure of hydrogen compression equipment and the working energy consumption of hydrogen compression equipment, and can reduce the energy consumption of the entire electrolytic hydrogen production system.

[0064] The O-ring seal in this application only requires one-time cold drawing during assembly, and the installation and replacement are very easy.

[0065] Although the preferred embodiments of this application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of this application.

[0066] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application also intends to include these changes and modifications.

Claims

1. A square pressurized alkaline electrolytic cell, characterized in that: include: The fixedly connected left end plate, electrolytic cell body and right end plate; The electrolytic cell body comprises a plurality of stacked electrolytic chambers; The electrolysis chamber includes: a square bipolar plate, the square bipolar plate is provided with an installation process hole and an inlet and outlet for circulation of alkali solution, grooves are respectively provided on both sides of the square bipolar plate, metal support meshes are fixed in the grooves, cathode electrodes and anode electrodes are respectively fixed on the metal support meshes on both sides of the square bipolar plate, the cathode electrode and the corresponding metal support meshes together constitute a cathode flow channel, the anode electrode and the corresponding metal support meshes together constitute an anode flow channel, and a diaphragm is provided between the cathode electrode and the anode electrode.

2. A square pressurized alkaline electrolytic cell according to claim 1, characterized in that: An intermediate electrode plate is arranged in the middle position of the electrolytic cell body, grooves are arranged on both sides of the intermediate electrode plate, metal support meshes are fixed in the grooves, anode electrodes are fixed to the metal support meshes on both sides of the intermediate electrode plate, the anode electrodes and the corresponding metal support meshes together constitute an anode flow channel, and the intermediate electrode plate and the square bipolar plates adjacent to the two sides thereof constitute an electrolysis chamber.

3. A square pressurized alkaline electrolytic cell according to claim 2, characterized in that: The middle plate is provided with a positive power terminal, and the left end plate and the right end plate are both provided with a negative power terminal; The left end plate and the right end plate are respectively provided with an alkali solution inlet and an alkali solution outlet, and are both provided with installation process holes and tightening bolt holes. The left end plate and the right end plate are both provided with a groove on the side adjacent to the electrolytic cell body, and a metal support mesh is fixed in the groove. The metal support meshes of the left end plate and the right end plate are respectively fixed with cathode electrodes, and the cathode electrodes and the corresponding metal support meshes together constitute a cathode flow channel. The left end plate and the square bipolar plate adjacent to the right side thereof constitute an electrolysis chamber, and the right end plate and the square bipolar plate adjacent to the left side thereof constitute an electrolysis chamber.

4. A square pressurized alkaline electrolytic cell according to claim 2, characterized in that: Inter-plate insulating pads are provided between adjacent square bipolar plates, between the left end plate and the electrolytic cell body, between the electrolytic cell body and the right end plate, and between the middle plate and the square bipolar plates on both sides; The inter-plate insulating pad is provided with a mounting process hole and a flow channel for the alkali solution to pass through.

5. A square pressurized alkaline electrolytic cell according to claim 4, characterized in that: The inter-board insulating pad is made of polyetheretherketone material.

6. A square pressurized alkaline electrolytic cell according to claim 2, characterized in that: Sealing grooves are provided on both sides of the square bipolar plate, on the side of the left end plate facing the electrolytic cell body, on the side of the right end plate facing the electrolytic cell body, and on both sides of the intermediate plate; An O-shaped sealing ring is placed in the sealing groove. The O-shaped sealing ring is initially O-shaped and is adapted to the shape of the sealing groove during installation.

7. A square pressurized alkaline electrolytic cell according to claim 6, characterized in that: The O-shaped sealing ring is made of EPDM material.

8. A square pressurized alkaline electrolytic cell according to claim 1, characterized in that: Bases are provided below the left end plate and the right end plate.

9. A square pressurized alkaline electrolytic cell according to claim 1, characterized in that: The left end plate, the electrolytic cell body and the right end plate are fixedly connected by a fastening device; The fastening device comprises: a tightening bolt, a spare tightening nut, a nut, a guide sleeve, a disc spring, a fixing ring, an insulating gasket and an insulating sleeve.

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