High-tightness pressure electrolytic cell

Abstract

The invention relates to the technical field of hydrogen production through water electrolysis, and aims to provide a high-tightness pressure electrolytic cell which realizes better sealing performance through a simpler structure. Therefore, the device comprises an end plate and an electrolysis module, a permanent magnet sealing structural part and a magnetofluid gasket are arranged in the electrolysis module, a dynamic groove is formed in the magnetofluid gasket, the magnetofluid gasket is clamped to the side face of a strong magnet on the outer ring of the permanent magnet sealing structural part through the dynamic groove, and the dynamic groove and an adjacent electrode plate are matched to form a closed groove body. And the dynamic groove is filled with magnetic fluid. Due to the adoption of the technical scheme, the magnetofluid is flexibly filled to dynamically compensate deformation, the pressure bearing limit of traditional sealing is broken through, the junction magnet forms basic clamping force, the magnetofluid adjusts local magnetic flux in real time, and uniform pressure distribution is achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of hydrogen production by electrolysis of water, and particularly relates to a high-sealing-degree pressure electrolytic tank. BACKGROUND

[0002] The electrolytic tank is a core device for realizing the conversion of electric energy and hydrogen energy, and through electrolysis of water, electric energy is converted into the chemical energy carrier form of hydrogen gas, so that energy storage and transfer are realized. In the prior art, the main technical point is how to improve the conversion efficiency of the entire electrolytic tank. For example, the utility model patent No. CN202222330063.6 “magnetic field enhanced water electrolytic tank electrode” discloses a magnetic field enhanced water electrolytic tank electrode for hydrogen production by electrolysis of water, which comprises an electrode sheet, a permanent magnet and an iron core array. The outer periphery of the electrode sheet is provided with an electrolyte inlet and two electrolyte outlets, the two electrolyte outlets are arranged at the two ends opposite to the electrolyte inlet, the middle of the electrode sheet is engraved with a concave-convex flow channel, the concave-convex flow channel is communicated with the electrolyte inlet and one of the electrolyte outlets; the center of the back of the electrode sheet and the center around the center are uniformly provided with a plurality of blind holes, and the plurality of iron cores in the iron core array are correspondingly arranged in the blind holes after being matched with the permanent magnet. The utility model can provide a uniform magnetic field for the electrode surface without losing the electrode reaction area and the electrode mechanical strength, promote the detachment of the electrode surface bubbles through the micro-magnetic fluid effect, increase the electrode electrochemical active area, reduce the electrolyte ohmic resistance, and improve the electrolysis of water efficiency.

[0003] But in the actual work application process, due to the electrolytic water efficiency of the electrolytic cell is improved, its internal pressure will increase by several times. Such pressure increase has an impact on the sealing of the whole electrolytic cell. In the process of electrolytic water, oxygen is generated at the anode, and hydrogen is generated at the cathode, at which time the sealing is required to ensure the separation of the gas. The electrolytic cell with good sealing can prevent gas from mixing through the diaphragm and sealing structure. If the sealing is poor, hydrogen and oxygen may mix inside, resulting in a significant decrease in the purity of the output gas, even if the output increases, it will affect the subsequent application. For this, the patent application number CN202410662302.9 invention patent application "Electrolytic cell for enhancing hydrogen production efficiency of alkaline water by magnetic field" in the prior art relates to an electrolytic cell for enhancing hydrogen production efficiency of alkaline water by magnetic field, belonging to the field of electrolytic hydrogen production. The electrolytic cell includes a plurality of magnetic enhancement bipolar plates, the stack adopts a bipolar configuration, and the plurality of magnetic enhancement bipolar plates are coupled in series. The gas / liquid inlets and outlets of the hydrogen side and the oxygen side of the electrolytic cell are independent. Among them, the magnetic enhancement bipolar plate includes a pole frame, a pole plate, a flow channel support net, a permanent magnet and a reaction electrode; the permanent magnet is arranged in the interior of the pole frame, the pole plate is arranged on both sides of the pole frame, and the substrate covers the permanent magnet; the flow channel support net and the reaction electrode are sequentially stacked on the pole plate. The magnetic field direction of the permanent magnet can adopt a horizontal or vertical configuration. The invention realizes the fusion of the magnetic field effect and the alkaline water hydrogen production electrolytic cell by configuring the permanent magnet, which can reduce the electrolysis overpotential, thereby reducing the energy consumption, and at the same time, improving the electrolytic water hydrogen production current density and accelerating the hydrogen production efficiency. As can be seen from the drawings of the invention, a large number of fixing bolts are arranged on the end cover to ensure the overall airtightness. Such structure actually improves the pressure limit, and it is difficult to achieve pressure balance during the working process, especially during the working process, the interaction of hydraulic pressure, gas pressure and external fastening force, and leakage may occur during the working process. At the same time, such a large number of bolts make the whole equipment heavier, and the installation and maintenance are not convenient. SUMMARY

[0004] The purpose of the present application is to provide a high sealing pressure electrolytic cell, which realizes better sealing performance through a simpler structure. Ensure that the whole electrolytic cell maintains the balance of internal pressure while improving the conversion efficiency, prolongs the service life of the whole equipment, and ensures the overall sealing of the equipment.

[0005] In order to achieve the object, the application discloses a high-sealing pressure electrolytic cell which is composed of end plates arranged on the left and right sides and a plurality of electrolytic modules fixed between the end plates. The electrolytic module comprises an anode electrode plate and a cathode electrode plate, and a permanent magnet sealing structure is arranged between the anode electrode plate and the cathode electrode plate. The permanent magnet sealing structure comprises a main body, a plurality of air passage through holes are arranged around the edge of the main body, and a strong magnet ring is arranged on the outer edge of the permanent magnet sealing structure. A magnetic fluid gasket is arranged between the anode electrode plate, the cathode electrode plate and the permanent magnet sealing structure. A dynamic groove is arranged on the magnetic fluid gasket and is clamped on the side surface of the strong magnet ring of the outer ring of the permanent magnet sealing structure. The dynamic groove and the adjacent electrode plate cooperatively form a closed groove body, and the dynamic groove is filled with magnetic fluid.

[0006] Preferably, the magnetic fluid adopts a perfluoropolyether carrier liquid, and the saturation magnetization is greater than 500Gs. The perfluoropolyether is resistant to high pressure / corrosion; and the high magnetic saturation particles with a saturation magnetization greater than 500Gs ensure a fast response.

[0007] Preferably, a power supply ear for externally connecting a power supply is arranged on each electrode plate, and the protruding height of the power supply ear is not less than 15mm. In this way, the power supply ear to be connected can be selected according to actual conditions.

[0008] Preferably, each component in the electrolytic module is circular and arranged concentrically.

[0009] Preferably, the main body of the permanent magnet sealing structure is made of PTFE hard plastic.

[0010] Preferably, three air passage through holes are arranged on the permanent magnet sealing structure, two of the three air passage through holes are used in pairs, and the other one is used alone.

[0011] Preferably, the air passage through holes between the plurality of electrolytic modules are aligned and conducted to each other.

[0012] Preferably, a magnet mounting groove is arranged in the middle of each electrode plate, and an isolation magnet is arranged in the magnet mounting groove. The isolation magnet is circular and arranged concentrically with the electrode plate.

[0013] Preferably, the outer side of the isolation magnet arranged in the electrode plate is wrapped by a magnet insulation film. The magnet insulation film is made of silicone or fluororubber in the application. The softness of the magnet insulation film is ensured, and the adhesion effect of the magnet is also ensured.

[0014] Further, the number of electrolytic modules in one electrolytic cell of the application is 3-5. Too many electrolytic modules will cause the device to be too complex, which is not conducive to daily use and maintenance. Too few electrolytic modules will result in too low conversion efficiency.

[0015] By adopting the technical scheme, the application provides stable support through the PTFE rigid framework, dynamic deformation compensation through the flexible filling of the magnetic fluid, breaks through the pressure limit of the traditional seal, forms the basic clamping force through the magnetic iron, adjusts the local magnetic flux in real time through the magnetic fluid, and realizes uniform pressure distribution. In the process of using the equipment, the vibration stress is dynamically dissipated through the isolation magnet, and the deformation of the electrode plate is inhibited; the perfluoropolyether-based magnetic fluid resists high-temperature and strong-etching environment, and guarantees long-service-life and stable operation of the sealing system. The whole realizes the core target of high-pressure sealing, high-efficiency conversion and long-term reliability. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and are used to explain the application, and do not constitute a limitation of the application. In the drawings: Figure 1 is a schematic diagram of the overall structure of a high-sealing-degree pressure electrolytic cell according to the application.

[0017] Figure 2 is a front view of a high-sealing-degree pressure electrolytic cell according to the application.

[0018] Figure 3 is a schematic diagram of the internal structure of a high-sealing-degree pressure electrolytic cell according to the application.

[0019] Figure 4 is a schematic diagram of the structure of a magnetic fluid gasket for a high-sealing-degree pressure electrolytic cell according to the application.

[0020] In the figure, 1 is an end plate, 2 is an electrolytic module, 21 is an anode electrode plate, 22 is a cathode electrode plate, 3 is a permanent magnet sealing structure, 31 is a main body, 32 is a gas passage hole, 33 is a strong magnet, 34 is a water passage hole, 4 is a magnetic fluid gasket, 41 is a dynamic groove, and 5 is an isolation magnet. DETAILED DESCRIPTION

[0021] The preferred embodiments of the application are described below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the application, and do not limit the application.

[0022] In order to clearly express the content involved in the application, first, the meanings of some abbreviations involved in the application are explained.

[0023] Among the existing technologies, the most common ones on the market are AWE alkaline water electrolysis electrolytic cells and PEM proton exchange membrane electrolytic cells. The AWE alkaline water electrolysis electrolytic cell is a mature industrial technology for realizing large-scale stable hydrogen production by using low-cost, long-life liquid KOH electrolyte as the core and non-noble metal electrodes, but it has the shortcoming of relatively low efficiency and slow dynamic response.

[0024] And PEM proton exchange membrane electrolyzer, namely proton exchange membrane electrolyzer is to utilize solid state perfluorosulfonic acid membrane to conduct H⁺, with noble metal as catalyst, realizes advanced technology of high efficient pure water hydrogen production, core features are: current density is as high as 1-6A / cm², millisecond level response, high pressure output can reach 70bar, hydrogen purity is >99.99%, but due to the working environment is pH ≈2 strong acid environment, therefore, rely on iridium, platinum catalyst causes high cost.The technical scheme of the present application is matched with PEM proton exchange membrane electrolyzer.

[0025] As Figures 1-4 The high sealing degree pressure electrolyzer of the present application is composed of the end plate 1 and the end plate 1 fixed between the plurality of electrolysis modules 2 arranged on the left and right sides, the electrolysis module 2 includes anode electrode plate 21 and cathode electrode plate 22, permanent magnet sealing structure 3 is arranged between anode electrode plate 21 and cathode electrode plate 22, the permanent magnet sealing structure 3 includes main body 31, a circular water passage through hole 34 is opened in the middle of the main body 31, a plurality of gas passage through holes 32 are opened around the edge of the main body 31, the main body 31 of the permanent magnet sealing structure 3 is made of PTFE hard plastic. Three gas passage through holes 32 are arranged on the permanent magnet sealing structure 3, two of the three gas passage through holes 32 are used in pairs, and the other is used alone. The gas passage through holes 32 between the plurality of electrolysis modules 2 are aligned and conducted.

[0026] In the electrolyzer, the sealing is fastened by the plastic of the sealing member to the edge. The outermost circle structure is mainly used to prevent liquid leakage. The present application is provided with annular strong magnet 33 on the outer edge of permanent magnet sealing structure 3, so that the edge part is firmly adsorbed with the electrode plate, and the sealing degree is additionally ensured. The strong magnet 33 is an annular magnet, and the larger the volume is, the greater the adsorption force is. Compared with the same type of electrolyzer of ordinary specification, the adsorption force is increased by at least 30%, and the pressure corresponding to 1.5Mpa or more is usually required.

[0027] Magnetic fluid gaskets 4 are arranged between the anode electrode plate 21 and the cathode electrode plate 22 and the permanent magnet sealing structure 3, and the magnetic fluid gaskets 4 are provided with dynamic grooves 41 and are clamped on the side of the strong magnet 33 of the outer ring of the permanent magnet sealing structure 3 through the dynamic grooves 41, the dynamic grooves 41 and the adjacent electrode plates cooperate to form a closed groove body, and the dynamic grooves 41 are filled with magnetic fluid. The magnetic fluid adopts perfluoropolyether carrier liquid, and the saturation magnetization is > 500Gs. The perfluoropolyether resists high pressure / corrosion; the high magnetic saturation particles of more than 500Gs ensure rapid response. Each electrode plate is provided with a power supply lug for external power supply, and the protruding height of the power supply lug is not less than 15mm. In this way, the increase of contact resistance can be avoided, and at the same time, the uneven distribution of reaction gas can also be avoided. The electrolysis module 2 is circular and concentrically arranged. A magnet mounting groove is arranged in the middle of each electrode plate, the magnet mounting groove is provided with an isolation magnet 5, and the isolation magnet 5 is circular and concentrically arranged with the electrode plate. It should be noted that the magnet is not adsorbed in the magnet mounting groove, but is kept in a dynamic balance by the magnetic force between the magnets. The outer side of the isolation magnet 5 arranged in the electrode plate is wrapped by a magnet insulation film. The magnet insulation film in the application is made of silicone or fluororubber material. It can actually play a triple protection role, namely, electrical insulation: blocking the current path between the magnet and the electrode to prevent short circuit of the high-voltage electrolytic cell; in the PEM proton exchange membrane electrolytic cell, it can resist strong acid corrosion to avoid oxidation failure of the magnet; the flexible material can also reduce the processing precision requirement, buffer vibration stress and prolong the service life of the magnet.

[0028] The number of electrolysis modules 2 in one electrolytic cell of the application is 3-5. Too many electrolysis modules 2 will make the device too complex, which is not conducive to daily use and maintenance. Too few will result in too low conversion efficiency. The working principle of the application in normal use is consistent with that of the existing electrolytic cell. However, in the additional permanent magnet sealing structure 3 of the electrolysis module 2 of the application, the main body 31 adopts a PTFE structure, which provides rigid support, and the strong magnet 33 and the isolation magnet 5 generate uniform magnetic clamping force to press the electrode plate and the sealing structure. In this way, the sealing degree in the equipment is improved, and dynamic pressure balance is maintained in the system.

[0029] PTFE (polytetrafluoroethylene) is a high polymer material polymerized from tetrafluoroethylene. The fluorine atoms in the molecular structure tightly wrap the carbon atoms, giving it extreme chemical inertness, high and low temperature resistance of -200℃-260℃, ultra-low friction coefficient (0.04), non-stickiness, excellent electrical insulation and weather resistance, and other core characteristics. The PTFE structure of the main body 31 of the application is synthesized by tetrafluoroethylene monomer, and then resin is generated by suspension or dispersion polymerization, and then special process forming is carried out by cold pressing and sintering. It is applied to the scene of sealing and corrosion resistance. And because in the scene described in the application, mechanical strength and radiation resistance do not need to be considered, it is the best choice of material.

[0030] When local pressure anomaly occurs during use: pressure change causes the magnetic gap between the strong magnets 33 in this area to narrow, and the narrowing of the magnetic gap brings about magnetic field enhancement, at which point the magnetic fluid in the dynamic groove 41 migrates and accumulates in this area. The volume of the accumulated magnetic fluid expands to the effect of pushing the polar plate back to its original position. The magnetic fluid completes self-regulation within 0.1 seconds, and the leakage rate is always maintained at <0.01 NL / h·m In addition, the concentric structure is adopted between the various components in the present application, and all parts are coaxially assembled to avoid seal failure caused by uneven load.

[0031] The following is a further description of the more common scenarios of the present application as an example.

[0032] Example 1: Assembly deviation caused by equipment installation. In the prior art, the entire electrolytic cell is fixed by bolts.

[0033] During the bolt fixing process, if the local deformation of the electrolytic cell is caused by the assembly deviation of the bolts, at least one permanent magnet sealing structure 3 in the electrolytic module 2 will no longer be fixed in parallel with the corresponding electrode plate due to uneven stress. At this time, the strong magnet 33 outside the permanent magnet sealing structure 3 will have a reduced distance from its adjacent strong magnet 33 due to external force, compared with the designed value. The magnetic field strength at the reduced distance is increased, and the magnetic fluid in the dynamic groove 41 migrates to the high magnetic field area driven by the Lorentz force. The nanoparticles in the magnetic fluid form chain-like aggregation under strong field, thereby causing local volume expansion. In the case of magnetic fluid expansion, the strong magnet 33 is pushed away in the opposite direction, so that it returns to the predetermined position. At this time, the magnetic field strength experienced by the magnetic fluid in the dynamic groove 41 decreases, and the entire system returns to the equilibrium condition and can operate stably.

[0034] This mechanism is used to automatically restore the deviation caused by uneven force or incorrect installation position of the bolt fixing during the installation of the end plate 1. It is equivalent to converting the correction process of assembly error into a physical process of magnetic fluid autonomous response. It brings the beneficial effects of reducing the assembly threshold and eliminating manual intervention, especially avoiding damage to the sealing surface caused by repeated adjustment. At the same time, it also paves the way for high-pressure design of the present application.

[0035] However, it should be noted that the range of such automatic correction is limited, and in actual use, it can generally meet the assembly error of ±2mm roughness. The assembly recovery capability is limited for larger errors. However, in actual work, the end plate 1 has a corresponding installation mold before installation, and generally there will be no large error, and for products with large errors, the abnormality can be found by observation, while errors below 2mm will have an adverse effect on the performance of the equipment, and it is also difficult to quickly find by naked eye. The present application is used to make up for this gap, improve the first-effect qualification rate, and effectively improve the one-time assembly qualification rate.

[0036] Example 2: Equipment in use, due to aging or damage, resulting in leakage mitigation process: leakage triggers magnetic fluid migration, leakage point pressure drops to form a negative pressure zone, the peripheral magnetic field distortion, magnetic fluid nanoparticles are attracted by the magnetic force lines to the leakage area directional migration. The viscosity of the perfluoropolyether carrier liquid is large, forming a high resistance layer in the leakage channel, the gas penetration speed drops. Nanoparticles gather and chain at the leakage point, local volume expansion, physical shrinkage of the leakage channel cross section. Magnetic fluid covers the damaged surface, converts gas leakage into liquid permeation, reduces the leakage rate. Under normal circumstances, the pressure sensor set by the outside responds at this time, and artificial intervention is carried out to detect pressure fluctuations. When the electrolysis current is detected to decrease or the gas production in the tank decreases, it can be judged that leakage occurs, and maintenance is carried out.

[0037] In this embodiment, although it cannot be automatically repaired, it can ensure that the leakage rate is stable when leakage occurs, the system maintains controllable leakage, and it remains in a maintainable state, and at the same time, a window period for maintenance is reserved in time, ensuring that the loss is within a controllable range.

[0038] Although the present application is disclosed in the preferred embodiments as described above, it is not intended to limit the scope of the application. Any person skilled in the art can make some improvements without departing from the scope of the application, that is, any equivalent improvement made according to the present application should be covered by the scope of the present application. In the description of the present application, the description of the terms "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In the description of the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments / ways or examples in a suitable manner. In addition, the skilled person can combine and combine the different embodiments / ways or examples described in the present application and the features of the different embodiments / ways or examples without contradiction.

[0039] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0040] Those skilled in the art should understand that the above embodiments are only for clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. Based on the above disclosure, other changes or modifications can also be made by those skilled in the art, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A high-sealing pressure electrolytic cell, characterized in that, It consists of multiple electrolysis modules fixed between end plates on the left and right sides; characterized in that each electrolysis module includes an anode electrode plate and a cathode electrode plate, with a permanent magnet sealing structure between the anode electrode plate and the cathode electrode plate. The permanent magnet sealing structure includes a main body with a circular water passage hole in the middle of the main body and multiple air passage holes around the edge of the main body. A ring-shaped strong magnet is provided on the outer edge of the permanent magnet sealing structure. Magnetorheological fluid gaskets are provided between the anode electrode plate, the cathode electrode plate, and the permanent magnet sealing structure. The magnetorheological fluid gaskets have dynamic grooves and are engaged with the side of the strong magnet on the outer edge of the permanent magnet sealing structure through the dynamic grooves. The dynamic grooves and their adjacent electrode plates cooperate to form a closed groove, which is filled with magnetorheological fluid.

2. The high-sealing pressure electrolytic cell according to claim 1, characterized in that, The magnetorheological fluid uses a perfluoropolyether carrier liquid and has a saturation magnetization of >500Gs.

3. The high-sealing pressure electrolytic cell according to claim 1, characterized in that, Each electrode plate is provided with a power supply ear for connecting an external power source, and the protrusion height of the power supply ear is not less than 15mm.

4. The high-sealing pressure electrolytic cell according to claim 1 or 2, characterized in that, All components in the electrolysis module are circular and concentrically arranged.

5. The high-sealing pressure electrolytic cell according to claim 1, characterized in that, The main body of the permanent magnet sealing structure is made of PTFE rigid plastic.

6. The high-sealing pressure electrolytic cell according to claim 4, characterized in that, The permanent magnet sealing structure is provided with three air passage holes, two of which are used in pairs and the other is used alone.

7. The high-sealing pressure electrolytic cell according to claim 5, characterized in that, The gas passages between multiple electrolysis modules are aligned and connected to each other.

8. The high-sealing pressure electrolytic cell according to claim 1, characterized in that, Each electrode plate has a magnet mounting groove in the middle, and an isolation magnet is installed in the magnet mounting groove. The isolation magnet is circular and placed concentrically with the electrode plate.

9. The high-sealing pressure electrolytic cell according to claim 8, characterized in that, The isolation magnets set in the electrode plate are wrapped with a magnetic insulating film on the outside.

10. The high-sealing pressure electrolytic cell according to claim 1, characterized in that, The number of electrolysis modules in an electrolytic cell is 3-5.

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