Water electrolysis system and application thereof

Abstract

The invention relates to the field of water electrolysis, and discloses a water electrolysis system and application thereof. The electrolytic bath comprises a bath body, a plurality of cathode electrodes and a plurality of anode electrodes, wherein the cathode electrodes and the anode electrodes are alternately arranged in the bath body. An ion exchange membrane is arranged between any adjacent cathode electrode and anode electrode; a cavitation device is arranged below each cathode electrode and each anode electrode, the cavitation devices are used for carrying out cavitation treatment on input electrolyte, and the treated electrolyte is respectively conveyed to the cathode electrodes and the anode electrodes for electrolysis to generate hydrogen and oxygen; a plurality of Venturi tubes stacked in a honeycomb shape are arranged in the cavitation device, and each Venturi tube is composed of an inlet, a contraction section, a throat, a diffusion section and an outlet which are connected in sequence. According to the water electrolysis system, the efficiency of hydrogen production through water electrolysis can be remarkably improved, the energy consumption of water electrolysis can be effectively reduced, and the system is simple in structure, easy to commercially implement and wide in industrial prospect.

Description

Technical Field

[0001] The present invention relates to the field of water electrolysis, and in particular to a water electrolysis system and applications thereof. Background Art

[0002] Hydrogen has an extremely high energy density, and its combustion product is water. As a renewable and environmentally friendly energy source, it has always attracted people's attention. At present, the rational use of hydrogen energy technology must improve the efficiency of hydrogen use on the basis of reducing costs. Excess electricity generated by power generation such as solar energy, wind energy, and geothermal energy can be used for water electrolysis, and the reaction is simple, so water hydrogen production technology has great advantages and is the key development direction of hydrogen production in the future. However, in the process of hydrogen production by water electrolysis, the high overpotential of the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) will increase the external applied voltage of the water electrolysis, resulting in high energy consumption, thereby reducing the hydrogen production efficiency. Therefore, reducing the overpotential of the oxygen evolution reaction and the hydrogen evolution reaction is the current key research direction of hydrogen production by water electrolysis.

[0003] At present, alkaline electrolytes are generally used for hydrogen production by water electrolysis. The technology of alkaline water electrolysis for hydrogen production is highly mature, with low equipment cost, and is more suitable for large-scale hydrogen production. It is the main choice for hydrogen production by water electrolysis. The disadvantage of alkaline water electrolysis for hydrogen production is that the energy efficiency is relatively low, which is about 60%. There is also the problem of carbonate deposition. Alkaline electrolytes may react with carbon dioxide in the air to form carbonates, which scale on the electrode surface and affect gas generation and transmission. In addition, the reason for the high overpotential of alkaline water electrolysis for hydrogen production is that the charge-induced transfer is water molecules rather than hydronium ions. The key to improving the efficiency of hydrogen evolution reaction (HER) in alkaline media is to improve the dissociation of water molecules and accelerate the formation of hydrogen intermediates. Reducing energy consumption is the key to hydrogen production in alkaline electrolyzers. The rate-controlling step is that water molecules on the cathode surface obtain electrons to form hydrogen and hydroxide ions (OH-). Therefore, improving the dissociation of water molecules and quickly forming hydrogen intermediates is the fundamental problem of solving energy consumption. The current common practice is to add strong oxidants such as potassium dichromate to oxidize the impurities on the electrode surface, increase the activity of the electrode surface, and reduce the cell pressure. However, potassium dichromate is a toxic and carcinogenic strong oxidant. It is classified as a Class I carcinogen by the International Agency for Research on Cancer and its use must be strictly controlled.

[0004] In addition, in the process of producing hydrogen by alkaline water electrolysis, a part of the energy is consumed to accelerate the flow of OH-, and the bubbles generated during the electrolysis process will adhere to the electrode surface, further hindering the improvement of electrode efficiency. In addition, there is also the problem of local overheating in the process of producing hydrogen by water electrolysis, which will affect the stability of the water electrolysis process. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems of excessively high energy consumption and low hydrogen production efficiency in the alkaline water electrolysis process in the prior art, and to provide a water electrolysis system and its application. The water electrolysis system provides a cavitation device in an electrolytic cell to perform cavitation treatment on an input electrolyte, and the treated electrolyte can form a variety of ions with high oxidation potentials, thereby accelerating the generation efficiency and purity of hydrogen in the electrolysis of water, and can also reduce bubbles in the electrolyte, reduce the hydrogen evolution overpotential in the reaction process, accelerate the separation of gases, and further save the energy consumption of the electrolysis of water.

[0006] In order to achieve the above-mentioned object, the present invention provides a water electrolysis system on one hand, wherein the electrolytic cell comprises a cell body, and a plurality of cathode electrodes and anode electrodes alternately arranged in the cell body;

[0007] An ion exchange membrane is provided between any adjacent cathode electrodes and anode electrodes;

[0008] A cavitation device is provided below each cathode electrode and each anode electrode, and the cavitation device is used to perform cavitation treatment on the input electrolyte, and after the treatment, the electrolyte is respectively transported to the cathode electrode and the anode electrode for electrolysis to generate hydrogen and oxygen;

[0009] The cavitation device is provided with a plurality of Venturi tubes stacked in a honeycomb shape, and the Venturi tubes are composed of an inlet, a contraction section, a throat, a diffusion section and an outlet connected in sequence.

[0010] Preferably, the diffusion angle of the diffusion section of the venturi tube is 6-7°.

[0011] Preferably, the ratio of the diameter of the throat to the length of the throat is 0.8-1.3.

[0012] Preferably, in the Venturi tube, the ratio of the length of the diffusion section to the length of the contraction section is 2-3:1.

[0013] Preferably, in the Venturi tube, the ratio of the length of the contraction section to the throat diameter is 1.8-2.5:1;

[0014] Preferably, in the Venturi tube, the ratio of the length of the diffusion section to the throat diameter is 3.5-4.5:1.

[0015] Preferably, an electrolyte inlet is provided at the bottom of the cell body of the electrolytic cell for inputting electrolyte into the electrolytic cell.

[0016] Preferably, a first control unit is provided at the electrolyte inlet for regulating the flow rate of the electrolyte delivered to the electrolytic cell.

[0017] Preferably, an electrolyte outlet is provided on the side wall of the electrolytic cell body for discharging the electrolyte after electrolysis.

[0018] Preferably, a second control unit is provided at the electrolyte outlet for regulating the flow rate of the electrolyte output from the electrolytic cell.

[0019] A second aspect of the present invention provides an application of the water electrolysis system in producing hydrogen and oxygen by electrolysis of water.

[0020] The electrolytic water system of the present invention provides a cavitation device in the electrolytic cell, and transports the input electrolyte to the venturi tube in the cavitation device for hydraulic cavitation treatment. After the cavitation treatment, a variety of substances with high oxidation potentials will be generated in the electrolyte, including hydroxyl free radicals OH - and H2O2, hydroxyl radicals OH formed after cavitation - It can pass through the ion exchange membrane in the electrolytic cell to reach the anode, where it loses electrons on the surface of the anode electrode to generate oxygen and water. In addition, the H2O2 produced by hydrodynamic cavitation can oxidize impurities on the electrode surface, thereby exposing more active sites on the electrode, reducing the cell pressure, and avoiding the use of toxic strong oxidants. At the same time, after the electrolyte is cavitated, it can also reduce the generation of bubbles in the water and reduce the overpotential of the reaction electrode. The electrolyte is hydrodynamically cavitated by the cavitation device, which changes the direction of the water flow in the electrolytic cell, impacts the cathode electrode and the anode electrode, and forms turbulent fluid on the surface of the positive and negative electrodes, further accelerating the escape speed of bubbles on the electrode surface during the electrolysis of water, thereby saving energy consumption for electrolysis of water. In addition, in the water electrolysis system described in the present invention, after the electrolyte is cavitated by the cavitation device, high temperature and high pressure will be generated at the moment when the bubbles generated by cavitation burst, so that the water temperature in the electrolytic cell can be increased to about 60°C, thereby reducing the energy consumption of heating the electrolytic cell. In the water electrolysis system described in the present invention, the electrolyte continuously flows in the electrolytic cell, thereby avoiding local overheating in the electrolytic cell, ensuring the uniformity of the temperature in the electrolytic cell, and thus ensuring the stable operation of the water electrolysis system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the water electrolysis system of the present invention;

[0022] Figure 2 is a schematic cross-sectional view of the cavitation device of the present invention;

[0023] Figure 3 It is a schematic diagram of the Venturi tube described in the present invention.

[0024] Description of Reference Numerals

[0025] 1 tank body; 2 cathode electrode;

[0026] 3 anode electrode; 4 ion exchange membrane;

[0027] 5 cavitation device; 6 first control unit;

[0028] 7 second control unit; 51 venturi tube;

[0029] 511 inlet; 512 contraction section;

[0030] 513throat; 514diffusion section;

[0031] 515 outlet; 8 delivery pumps. DETAILED DESCRIPTION

[0032] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0033] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0034] In the present invention, the schematic diagram of the water electrolysis system is as follows Figure 1 As shown, the water electrolysis system includes an electrolytic cell, which includes a cell body 1, and cathode electrodes 2 and anode electrodes 3 alternately arranged in the cell body 1. An ion exchange membrane 4 is arranged between any adjacent cathode electrodes 2 and anode electrodes 3, and the ion exchange membrane 4 is used to transmit ions during water electrolysis.

[0035] Specifically, the cathode electrode 2 undergoes a hydrogen evolution reaction by electrolysis of water. The water in the electrolyte undergoes a hydrogen evolution reaction (HER, 4H2O+4e - =2H2↑+4OH - ) is electrolyzed near the cathode electrode 2 to produce hydrogen and OH - , hydrogen is collected for clean energy, OH - Pass through the ion exchange membrane 4 and enter the vicinity of the anode electrode 3; OH - Through oxygen evolution reaction (OER, 4OH - +4e - =2H2O+O2↑) produces oxygen near the anode electrode 3.

[0036] In the present invention, the specific composition of the ion exchange membrane 4 disposed in the electrolytic cell is not limited, and it can be a common ion exchange membrane in the art.

[0037] In the present invention, the material or composition of the cathode electrode 2 and the anode electrode 3 in the electrolytic cell is not limited, and they can also be electrode materials commonly used in the art for water electrolysis in an alkaline environment. For example, the cathode electrode 2 can be a silver electrode, a copper electrode or a nickel electrode; the anode electrode 3 can be a graphite electrode.

[0038] In the present invention, a cavitation device 5 is provided below each cathode electrode 2 and each anode electrode 3, and the cavitation device 5 is used to cavitation the input electrolyte, and after the treatment, it is respectively transported to the cathode electrode 2 and the anode electrode 3 for electrolysis to produce hydrogen and oxygen. It can be understood that a cavitation device 5 is provided below any cathode electrode 2 or anode electrode 3, and the cavitation device 5 is arranged one-to-one with the cathode electrode 2 and the anode electrode 3. Cavitation is a unique physical phenomenon in the field of hydrodynamics, which refers to the phenomenon that at a certain temperature, the liquid vaporizes or forms a gas phase inside it due to the reduction of pressure. Usually, hydraulic cavitation is generated by the change of the flow rate and pressure of the liquid. The cross-section of the fluid channel is reduced by using a throttle valve, and the flow rate and kinetic energy are increased by reducing the pressure. At the same time, boundary layer separation and turbulence will occur. Due to local fluid turbulence, a large amount of energy is lost in the form of permanent pressure drop. The liquid pressure decreases with the increase of kinetic energy. When the local pressure drops to the cavitation threshold pressure, a cavity begins to be generated. When the pressure recovers or rises above the cavitation threshold, the cavity collapses and the microjet generates turbulence downstream of the liquid contraction. When the hydrodynamic cavitation bubble ruptures, there is a serious hydrodynamic cavitation effect, which affects the surrounding liquid environment in the form of thermal, mechanical and chemical effects.

[0039] In the present invention, the input electrolyte is first subjected to cavitation treatment by setting a cavitation device 5, and then the cavitated electrolyte is subjected to hydrogen evolution reaction and oxygen evolution reaction at the cathode electrode 2 and the anode electrode 3 respectively, so that the hydraulic cavitation and the electrolysis of water are deeply combined successfully, thereby utilizing the thermal effect, mechanical effect and chemical effect generated after cavitation to enhance the effect of hydrogen production by electrolysis of water and save the energy consumption of electrolysis of water.

[0040] In the present invention, the OH- generated after the input electrolyte is cavitated by the cavitation device 5 can pass through the ion exchange membrane 4 to reach the anode electrode 3, and lose electrons on the surface of the anode electrode 3 to obtain oxygen and water molecules, thereby reducing the amount of solute added to the alkaline electrolyte, and further making the hydrogen prepared by the hydrogen evolution reaction more pure. And the generated OH - It can react with inorganic salts in water to form precipitates and remove them from the water, thereby reducing inorganic salt scaling.

[0041] In the present invention, the H2O2 generated after the input electrolyte is cavitated by the cavitation device 5 has strong oxidizing properties, which can oxidize the impurities on the surface of the electrode, thereby further enhancing the activity of the electrode, and can also reduce the cell pressure of the electrolytic cell. It can also avoid the use of toxic strong oxidants commonly used in the prior art, thereby promoting the development of green industry.

[0042] In the water electrolysis system described in the present invention, the cavitated electrolyte can reduce the content of bubbles in the water, and can further take away the bubbles generated by the electrolysis reaction on the electrode surface, thereby reducing the overpotential in the water electrolysis process (i.e., the electrical energy required to promote the reaction) and the internal resistance of the electrolyte, saving energy consumption for water electrolysis. In addition, the electrolyte is hydraulically cavitated by the cavitation device 5, which changes the direction of water flow in the electrolytic cell, impacts the anode and cathode electrodes, and forms turbulent flow on the surfaces of the anode and cathode electrodes, which accelerates the escape velocity of the gas generated by electrolysis during the water electrolysis process, further exposes more active sites on the electrodes, and realizes low-energy operation of the water electrolysis system.

[0043] In the water electrolysis system of the present invention, the water flow in the electrolytic cell is constantly disturbed by the arrangement of the cavitation device 5, thereby avoiding local overheating of the electrolytic cell, ensuring uniform temperature in the electrolytic cell and stable operation of the electrolysis process. In addition, the electrolyte in the water electrolysis system of the present invention circulates continuously during the electrolysis process, further ensuring the stability of the temperature in the electrolytic cell.

[0044] In a specific embodiment, in the electrolytic cell, during the cavitation process performed by the cavitation device 5, high temperature and high pressure are generated at the moment when the bubbles generated by cavitation collapse, which can gradually increase the temperature of the electrolytic water solution to meet the temperature requirement of the electrolytic water, thereby reducing the energy consumption of the electrolytic cell heating device in heating the electrolytic cell, further saving the cost of electrolytic water, and improving the efficiency of electrolytic water.

[0045] In a specific embodiment, the cavitation device 5 is provided with a plurality of venturi tubes 51 stacked in a honeycomb shape. The cross-sectional schematic diagram of the cavitation device 5 is as follows: Figure 2 As shown. Specifically, the cavitation device 5 includes a shell and an inner cavity, in which a plurality of venturi tubes 51 are closely stacked in a honeycomb shape in the same direction and manner, and the input electrolyte is transported to the venturi tubes 51 for cavitation treatment. In particular, the cavitation device 5 described in the present invention can also be a perforated plate cavitation device and a rotary cavitation device commonly used in the art, and more preferably the structure defined in the present invention. The structure of the cavitation device 5 described in the present invention can make the degree of hydraulic cavitation of the electrolyte more intense, which is more conducive to improving the efficiency of water electrolysis.

[0046] In the present invention, the structural schematic diagram of the venturi tube 51 is as follows Figure 3 As shown, specifically, the venturi tube 51 is composed of an inlet 511, a contraction section 512, a throat 513, a diffusion section 514 and an outlet 515 connected in sequence. The electrolyte enters the venturi tube 51 through the inlet 511, passes through the contraction section 512, the throat 513, and the diffusion section 514 in sequence for cavitation, and then is discharged through the outlet 515. The discharged electrolyte is electrolyzed in the cathode electrode 2 and the anode electrode 3 to generate hydrogen and oxygen.

[0047] In the present invention, the cavitation device 5 realizes cavitation treatment of the electrolyte through the venturi tube 51, and the cavitated electrolyte undergoes electrolysis reaction at the cathode electrode 2 and the anode electrode 3 to obtain hydrogen and oxygen.

[0048] In a preferred embodiment, the diffusion angle of the diffusion section 514 of the venturi tube 51 is 6-7°, more preferably 6.3-6.8°, and further preferably 6.5°. Under this condition, the degree of hydrodynamic cavitation of the electrolyte input into the venturi tube 51 is the most intense, which is most conducive to improving the efficiency of water electrolysis. Specifically, the diffusion angle of the diffusion section 514 of the venturi tube 51 can be 6°, 6.1°, 6.2°, 6.3°, 6.4°, 6.5°, 6.6°, 6.7°, 6.8°, 6.9° or 7°.

[0049] In a preferred embodiment, the ratio of the diameter of the throat 513 of the venturi tube 51 to the length of the throat 513 is 0.8-1.3, more preferably 0.9-1.1, and most preferably 1. Under this condition, the degree of hydrodynamic cavitation of the electrolyte input into the venturi tube 51 is the most intense, which is most conducive to improving the operating efficiency of the water electrolysis system. Specifically, the ratio of the diameter of the throat 513 of the venturi tube 51 to the length of the throat 513 can be 0.8, 0.9, 1, 1.1, 1.2 or 1.3.

[0050] In a preferred embodiment, in the venturi tube 51, the ratio of the length of the diffuser section 514 to the length of the contraction section 512 is 1.9-3:1, more preferably 2-2.5:1, and further preferably 2:1. Under this condition, the degree of hydrodynamic cavitation of the electrolyte input into the venturi tube 51 is the most intense, which is more conducive to improving the operating efficiency of the water electrolysis system. Specifically, the ratio of the length of the diffuser section 514 to the length of the contraction section 512 can be 1.9:1, 2:1, 2.5:1 or 3:1.

[0051] In a preferred embodiment, in order to make the degree of hydrodynamic cavitation of the electrolyte input into the venturi tube 51 more intense and to improve the hydrogen production efficiency of the water electrolysis system to a greater extent, in the venturi tube 51, the ratio of the length of the contraction section 512 to the diameter of the throat 513 is 1.8-2.5:1, preferably 2-2.3:1, and more preferably 2:1. Specifically, the ratio of the length of the contraction section 512 to the diameter of the throat 513 can be 1.8:1, 1.9:1, 2:1, 2.1:1, 2.3:1, 2.4:1 or 2.5:1.

[0052] In a preferred embodiment, in order to make the degree of hydrodynamic cavitation of the electrolyte input into the venturi tube 51 more intense and to improve the hydrogen production efficiency of the water electrolysis system to a greater extent, in the venturi tube 51, the ratio of the length of the diffuser section 514 to the diameter of the throat 513 is 3.5-4.5:1, preferably 3.9-4.2:1, and more preferably 4:1. Specifically, the ratio of the length of the diffuser section 514 to the diameter of the throat 513 can be 3.5:1, 3.8:1, 3.9:1, 4:1, 4.1:1, 4.2:1, 4.3:1, 4.4:1 or 4.5:1.

[0053] In a preferred embodiment, in the electrolytic cell, an electrolyte inlet is provided at the bottom of the cell body 1 of the electrolytic cell for inputting electrolyte into the electrolytic cell. Preferably, a plurality of electrolyte inlets may be provided at the bottom of the cell body 1 of the electrolytic cell for transporting electrolyte to the cathode electrode 2 and the anode electrode 3 for electrolyzing water.

[0054] In a preferred embodiment, a first control unit 6 is provided at the electrolyte inlet for regulating the flow rate of the electrolyte delivered to the electrolytic cell body 1. Specifically, the first control unit 6 may be a switch valve or other equipment commonly used in the art.

[0055] In a preferred embodiment, an electrolyte outlet is provided on the side wall of the cell body 1 of the electrolytic cell for outputting the electrolyzed electrolyte.

[0056] In a preferred embodiment, a second control unit 7 is provided at the electrolyte outlet for regulating the flow rate of the electrolyte output from the electrolytic cell. Specifically, the second control unit 7 may be a switch valve or other device commonly used in the art.

[0057] In a specific embodiment, a delivery pump 8 is further provided between the electrolyte inlet and the first control unit 6 for delivering the electrolyte to the cathode electrode 2 and the anode electrode 3 for electrolysis.

[0058] In some specific embodiments, when the concentration of the electrolyte in the electrolyte is 25%-30%, the first control unit 6 is turned off, and the electrolyte is transported to the cavitation device 5 through the delivery pump 8 for cavitation treatment. The treated electrolyte undergoes hydrogen evolution reaction and oxygen evolution reaction at the cathode electrode 2 and the anode electrode 3, respectively. The reacted electrolyte is discharged through the electrolyte outlet and then returned to the electrolytic cell through the delivery pump 8 for use; when the concentration of the electrolyte in the electrolyte is greater than 30%, the first control unit 6 and the second control unit 7 are turned on, the reacted electrolyte is discharged through the electrolyte outlet, and then mixed with the desalted water transported from the outside, and then the mixed liquid is returned to the cavitation device 5 in the electrolytic cell through the delivery pump 8 for cavitation treatment, and then the electrolysis reaction continues at the cathode electrode 2 and the anode electrode 3.

[0059] The present invention can also provide an application of the water electrolysis system in the production of hydrogen and oxygen by water electrolysis. The present invention applies a cavitation device to the water electrolysis system, first performs cavitation treatment on the electrolyte, and then uses the cavitation-treated electrolyte for water electrolysis, thereby effectively improving the efficiency of water electrolysis and effectively reducing the overpotential required in water electrolysis, further saving the energy consumption of water electrolysis, and further improving the purity of hydrogen obtained by electrolysis, further expanding the industrial application of water electrolysis to produce hydrogen, and laying a solid foundation for the development of new energy.

[0060] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto.

[0061] The electrolysis water system used in the following embodiments is combined with reference to Figure 1 The water electrolysis system comprises an electrolytic cell, wherein the electrolytic cell comprises a cell body 1, and a cathode electrode 2 and an anode electrode 3 alternately arranged in the cell body 1;

[0062] An ion exchange membrane 4 is provided between any adjacent cathode electrodes 2 and anode electrodes 3;

[0063] A cavitation device 5 is provided below each cathode electrode 2 and each anode electrode 3.

[0064] An electrolyte inlet is provided at the bottom of the electrolytic cell body 1, a first control unit 6 is provided at the electrolyte inlet, an electrolyte outlet is provided on the side wall of the electrolytic cell body 1, a second control unit 7 is provided at the electrolyte outlet; the first control unit 6 and the second control unit 7 are both switch valves;

[0065] A delivery pump 8 is also provided between the electrolyte inlet and the first control unit 6;

[0066] The cavitation device 5 is provided with a plurality of venturi tubes 41 stacked in a honeycomb shape, and the venturi tube 51 is composed of an inlet 511, a contraction section 512, a throat 513, a diffusion section 514 and an outlet 515 connected in sequence. The diffusion angle of the diffusion section 514 of the venturi tube 51 is 6.5°, and the ratio of the diameter of the throat 513 of the venturi tube 41 to the length of the throat 513 is 1;

[0067] In the Venturi tube 51, the ratio of the length of the diffuser section 514 to the length of the contraction section 512 is 2:1, the ratio of the length of the contraction section 512 to the diameter of the throat 513 is 2:1, and the ratio of the length of the diffuser section 514 to the diameter of the throat 513 is 4:1.

[0068] Example 1

[0069] When the concentration of the electrolyte in the electrolyte is 25%-30%, the first control unit 6 is turned off, and the electrolyte is transported to the venturi tube 51 in the cavitation device 5 through the electrolyte inlet by the delivery pump 8 for cavitation treatment, and the treated electrolyte undergoes hydrogen evolution reaction and oxygen evolution reaction at the cathode electrode 2 and the anode electrode 3 respectively, and the reacted electrolyte is discharged through the electrolyte outlet and then returned to the electrolytic cell through the delivery pump 8 for electrolysis reaction;

[0070] When the concentration of electrolyte in the electrolyte gradually increases to greater than 30%, the first control unit 6 and the second control unit 7 are turned on to discharge the reacted electrolyte through the electrolyte outlet, and then mixed with desalted water transported from the outside, and then the delivery pump 8 is used to return the mixed electrolyte through the electrolyte inlet to the Venturi tube 51 in the cavitation device 5 for cavitation treatment, and then water electrolysis reaction is carried out at the cathode electrode 2 and the anode electrode 3.

[0071] The water electrolysis system of the present invention can significantly improve the efficiency of hydrogen production by water electrolysis, and can also effectively save the energy consumption of water electrolysis. In addition, the water electrolysis system of the present invention has a simple structure, is easy to commercialize, and has broad industrial prospects.

[0072] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A water electrolysis system, characterized in that: The water electrolysis system comprises an electrolytic cell, wherein the electrolytic cell comprises a cell body (1), and a plurality of cathode electrodes (2) and anode electrodes (3) alternately arranged in the cell body (1); An ion exchange membrane (4) is provided between any adjacent cathode electrodes (2) and anode electrodes (3); A cavitation device (5) is provided below each cathode electrode (2) and each anode electrode (3), and the cavitation device (5) is used to perform cavitation treatment on the input electrolyte, and after the treatment, the electrolyte is respectively transported to the cathode electrode (2) and the anode electrode (3) for electrolysis to generate hydrogen and oxygen; The cavitation device (5) is provided with a plurality of Venturi tubes (51) stacked in a honeycomb shape, and the Venturi tubes (51) are composed of an inlet (511), a contraction section (512), a throat (513), a diffusion section (514) and an outlet (515) connected in sequence.

2. The water electrolysis system according to claim 1, characterized in that: The diffusion angle of the diffusion section (514) of the venturi tube (51) is 6-7°.

3. The water electrolysis system according to claim 1 or 2, characterized in that: The ratio of the diameter of the throat (513) to the length of the throat (513) is 0.8-1.

3.

4. The water electrolysis system according to any one of claims 1 to 3, characterized in that: In the Venturi tube (51), the ratio of the length of the diffusion section (514) to the length of the contraction section (512) is 1.9-3:

1.

5. The water electrolysis system according to any one of claims 1 to 4, characterized in that: In the Venturi tube (51), the ratio of the length of the contraction section (512) to the diameter of the throat (513) is 1.8-2.5:1; and / or In the Venturi tube (51), the ratio of the length of the diffusion section (514) to the diameter of the throat (513) is 3.5-4.5:

1.

6. The water electrolysis system according to claim 1, characterized in that: An electrolyte inlet is provided at the bottom of the cell body (1) of the electrolytic cell for inputting electrolyte into the electrolytic cell.

7. The water electrolysis system according to claim 6, characterized in that: A first control unit (6) is provided at the electrolyte inlet for regulating the flow rate of the electrolyte delivered to the electrolytic cell.

8. The water electrolysis system according to claim 1, characterized in that: An electrolyte outlet is provided on the side wall of the cell body (1) of the electrolytic cell for discharging the electrolyte after electrolysis.

9. The water electrolysis system according to claim 8, characterized in that: A second control unit (7) is provided at the electrolyte outlet for regulating the flow rate of the electrolyte output from the electrolytic cell.

10. Use of the water electrolysis system according to any one of claims 1 to 9 in producing hydrogen and oxygen by electrolysis of water.

Images