Water electrolysis hydrogen production system, and method and apparatus for controlling gas purity in water electrolysis hydrogen production process

Abstract

A water electrolysis hydrogen production system, and a method and apparatus for controlling gas purity in a water electrolysis hydrogen production process, relating to the technical field of electrolytic hydrogen production. The water electrolysis hydrogen production system comprises an electrolytic cell, a hydrogen gas-liquid separation unit, and an oxygen gas-liquid separation unit. A hydrogen side gas outlet of the electrolytic cell is connected to the hydrogen gas-liquid separation unit, and an oxygen side gas outlet of the electrolytic cell is connected to the oxygen gas-liquid separation unit. A liquid outlet of the hydrogen gas-liquid separation unit is connected to a first pipeline; a liquid outlet of the oxygen gas-liquid separation unit is connected to a second pipeline; the first pipeline and the second pipeline are converged and then connected to one end of an alkaline liquor backflow main pipeline; and the other end of the alkaline liquor backflow main pipeline is connected to an oxygen side pipeline and a hydrogen side pipeline. The hydrogen side pipeline is connected to a hydrogen side alkaline liquor flow channel inlet of the electrolytic cell, and the oxygen side pipeline is connected to an oxygen side alkaline liquor flow channel inlet of the electrolytic cell. The hydrogen side pipeline and the oxygen side pipeline are each provided with a flow measurement assembly and a flow adjustment assembly. The flows at the hydrogen side inlet and the oxygen side inlet of the electrolytic cell are respectively controlled, and the concentration of the alkaline liquor is kept consistent at the two sides.

Description

Water electrolysis hydrogen production system, method and device for controlling gas purity during water electrolysis hydrogen production process

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent disclosures with application number 202310796877.5, filed with the Patent Office of China on June 30, 2023, entitled “A device, system and method for controlling gas purity in a water electrolysis hydrogen production system”, application number 202321696680.6, filed with the Patent Office of China on June 30, 2023, entitled “A system for producing hydrogen by alkaline water electrolysis”, and application number 202321815572.6, filed with the Patent Office of China on July 11, 2023, entitled “Electrolyzer”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the technical field of electrolytic hydrogen production, and in particular to a water electrolytic hydrogen production system, and a method and device for controlling gas purity during the water electrolytic hydrogen production process. Background Art

[0004] Currently, filter-press bipolar electrolyzers are commonly used in the field of alkaline water electrolysis for hydrogen production. This type of electrolyzer consists of several stacked pole frames and bipolar plates mounted within the pole frames. The pole frames and bipolar plates form a pole frame assembly, which creates multiple electrolysis chambers within the electrolyzer for containing electrolyte and conducting electrolysis reactions. Each pair of pole frames is separated by a diaphragm, dividing the electrolysis chambers into cathode and anode chambers. The cathode chamber undergoes a hydrogen ion reduction reaction to produce hydrogen, while the anode chamber undergoes a hydroxide ion oxidation reaction to produce oxygen.

[0005] The traditional alkaline water electrolysis hydrogen production system has a stable input power supply, so the pressure of the hydrogen production system is stable, the electrolyte flow is stable, and the purity of the obtained gas is also relatively stable. However, for new energy alkaline water electrolysis hydrogen production systems, such as wind and solar coupled hydrogen production systems, renewable energy sources such as wind and solar energy have the characteristics of randomness, volatility and uncertainty. When the load is low, the oxygen production rate will be lower than the crossover rate of hydrogen, resulting in an increase in the hydrogen content in the oxygen. In addition, because hydrogen has a high permeability, hydrogen will also penetrate through the diaphragm to the oxygen side, resulting in the phenomenon of hydrogen in oxygen. When the hydrogen content in oxygen exceeds 4%, there is a risk of explosion.

[0006] Overview

[0007] The purpose of this application is to provide a water electrolysis hydrogen production system, a method and device for controlling gas purity during water electrolysis hydrogen production.

[0008] In a first aspect, the present application provides a water electrolysis hydrogen production system, the system comprising an electrolyzer, a hydrogen gas-liquid separation unit, and an oxygen gas-liquid separation unit;

[0009] The liquid outlet of the hydrogen gas-liquid separation unit is connected to a first pipeline, the liquid outlet of the oxygen gas-liquid separation unit is connected to a second pipeline, the first pipeline and the second pipeline are connected to one end of the alkali solution reflux main pipeline after merging, and the other end of the alkali solution reflux main pipeline is connected to an oxygen side pipeline and a hydrogen side pipeline in parallel; the hydrogen side pipeline is connected to the hydrogen side alkali solution flow channel inlet of the electrolyzer, and the oxygen side pipeline is connected to the oxygen side alkali solution flow channel inlet of the electrolyzer; the hydrogen side pipeline is provided with a first flow detection component and a first flow regulation component; the oxygen side pipeline is provided with a second flow detection component and a second flow regulation component;

[0010] The hydrogen-side gas outlet of the electrolyzer is connected to the hydrogen gas-liquid separation unit, and the oxygen-side gas outlet of the electrolyzer is connected to the oxygen gas-liquid separation unit.

[0011] Optionally, the system further includes a control unit, the first flow detection component and the second flow detection component are electrically connected to the control unit respectively, and the first flow regulation component and the second flow regulation component are electrically connected to the control unit respectively.

[0012] Optionally, the first flow regulating component includes a first variable frequency pump, and the second flow regulating component includes a second variable frequency pump.

[0013] Optionally, a alkali solution circulation pump is provided on the alkali solution reflux main line, the first flow regulating component includes a first regulating valve, and the second flow regulating component includes a second regulating valve.

[0014] Optionally, the system further comprises an alkali liquid cooler, and the alkali liquid cooler is arranged on the alkali liquid reflux main line.

[0015] Optionally, the hydrogen side pipeline is further provided with a first control valve, which is used to control the circulation and cutoff of the hydrogen side pipeline and control the single-phase flow of the liquid in the hydrogen side pipeline; the oxygen side pipeline is also provided with a second control valve, which is used to control the circulation and cutoff of the oxygen side pipeline and control the single-phase flow of the liquid in the oxygen side pipeline.

[0016] Optionally, the electrolytic cell includes a positive electrode, a first negative electrode and a second negative electrode, the positive electrode is located in the middle of the electrolytic cell, and the first negative electrode and the second negative electrode are respectively located at two ends of the electrolytic cell.

[0017] Optionally, the system comprises at least two electrolytic cells,

[0018] The hydrogen-side gas outlet of each electrolyzer is connected to the feed port of the hydrogen gas-liquid separation unit;

[0019] The oxygen-side gas outlet of each electrolytic cell is connected to the feed port of the oxygen gas-liquid separation unit.

[0020] Optionally, the system further comprises:

[0021] A gas purity detection component is electrically connected to the control unit and is capable of detecting the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system.

[0022] Optionally, the electrolytic cell comprises:

[0023] A tank body, wherein a plurality of electrolysis chambers are provided in the tank body, each of the electrolysis chambers includes an anode region and a cathode region, a first electrode plate is provided in the tank body, and a first cavity and a second cavity are formed in the first electrode plate;

[0024] a first flow field structure comprising a first liquid inlet channel and a first liquid distribution channel provided in the tank wall of the tank body, wherein the first liquid distribution channel is used to communicate with the plurality of anode regions respectively and to communicate with the first liquid inlet channel through the first cavity; and

[0025] The second flow field structure includes a second liquid inlet channel and a second liquid distribution channel arranged in the groove wall of the groove body, and the second liquid distribution channel is used to communicate with the multiple cathode areas respectively and communicate with the second liquid inlet channel through the second cavity.

[0026] Optionally, the electrolytic cell further includes a second electrode plate, which is symmetrically arranged on both sides of the first electrode plate in the extension direction of the cell body and spaced apart from the second electrode plate, and the first liquid inlet of the first liquid inlet channel and the second liquid inlet of the second liquid inlet channel are both arranged on the second electrode plate.

[0027] Optionally, the electrolytic cell further includes a second electrode plate, a plurality of first electrode plates are arranged at equal intervals on one side of the second electrode plate along the extension direction of the cell body, and the first liquid inlet of the first liquid inlet channel and the second liquid inlet of the second liquid inlet channel are both arranged on the second electrode plate.

[0028] Optionally, a plurality of the first flow field structure and a plurality of the second flow field structure are provided respectively.

[0029] Optionally, a plurality of the first flow field structures and a plurality of the second flow field structures are alternately arranged along the circumference of the trough body.

[0030] Optionally, the first cavity and the second cavity have the same volume.

[0031] In a second aspect, the present application further provides a method for controlling gas purity during water electrolysis hydrogen production, the method comprising:

[0032] Obtaining the hydrogen content in the oxygen produced by the hydrogen production system and the oxygen content in the hydrogen;

[0033] When the hydrogen content in the oxygen is greater than a first content value, increasing the electrolyte flow rate at the oxygen-side flow channel inlet of the electrolyzer and / or decreasing the electrolyte flow rate at the hydrogen-side flow channel inlet of the electrolyzer until the hydrogen content in the oxygen is less than or equal to a first target value;

[0034] When the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is increased and / or the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is decreased until the oxygen content in the hydrogen is less than or equal to the second target value.

[0035] Optionally, when the hydrogen content in the oxygen is greater than the first content value, the electrolyte flow rate at the oxygen-side flow channel inlet of the electrolyzer is increased and / or the electrolyte flow rate at the hydrogen-side flow channel inlet of the electrolyzer is decreased until the hydrogen content in the oxygen is less than or equal to the first target value:

[0036] When the hydrogen content in the oxygen is greater than a first content value, periodically increasing the electrolyte flow rate at the oxygen-side flow channel inlet of the electrolyzer to increase the first flow rate value and / or decreasing the electrolyte flow rate at the hydrogen-side flow channel inlet of the electrolyzer to decrease the second flow rate value at intervals of a first time value until the hydrogen content in the oxygen is less than or equal to a first target value; and / or,

[0037] When the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is increased and / or the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is decreased until the oxygen content in the hydrogen is less than or equal to the second target value:

[0038] When the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is periodically increased to a third flow rate value and / or the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is periodically decreased to a fourth flow rate value at intervals of a second time value until the oxygen content in the hydrogen is less than or equal to the second target value.

[0039] Optionally, the first content value is 0.5% to 1.5% by volume; and / or,

[0040] The first time value is 0.5 to 10 hours, preferably 2 to 8 hours; and / or,

[0041] The first flow rate value is 0.5% to 1% of the electrolyte flow rate at the oxygen side flow channel inlet before the adjustment; and / or,

[0042] The second flow rate value is 0.5% to 1% of the electrolyte flow rate at the hydrogen side flow channel inlet before the adjustment; and / or,

[0043] The first target value is 0.5% to 1.5% by volume; and / or,

[0044] The second content value is 0.5% to 1.5% by volume; and / or,

[0045] The second time value is 0.5 to 10 hours, preferably 2 to 8 hours; and / or,

[0046] The third flow rate value is 0.5% to 1% of the electrolyte flow rate at the hydrogen side flow channel inlet before the adjustment; and / or,

[0047] The fourth flow rate value is 0.5% to 1% of the electrolyte flow rate at the oxygen side flow channel inlet before the adjustment; and / or,

[0048] The second target value is a volume fraction of 0.5% to 1.5%.

[0049] In a third aspect, the present application further provides a device for controlling gas purity in a water electrolysis hydrogen production system, comprising:

[0050] a controller unit configured to determine adjustment values ​​of the electrolyte flow rates at the oxygen-side flow channel inlet and the electrolyte flow rates at the hydrogen-side flow channel inlet of the electrolyzer based on the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system, and the electrolyte flow rates at the oxygen-side flow channel inlet and the electrolyte flow rates at the hydrogen-side flow channel inlet of the electrolyzer;

[0051] a gas purity detection component, the gas purity detection component being electrically connected to the controller unit and configured to detect the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system;

[0052] a flow detection component electrically connected to the controller unit and configured to respectively detect the electrolyte flow rate at the oxygen-side flow channel inlet and the electrolyte flow rate at the hydrogen-side flow channel inlet of the electrolyzer; and

[0053] A flow regulating component is electrically connected to the controller unit and is configured to separately regulate the electrolyte flow rates at the oxygen-side flow channel inlet and the electrolyte flow rates at the hydrogen-side flow channel inlet of the electrolyzer.

[0054] Modifications based on supplementary requirements

[0055] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below.

[0056] BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0058] FIG1 is a schematic diagram of a first embodiment of a water electrolysis hydrogen production system provided in an embodiment of the present application;

[0059] FIG2 is a schematic diagram of a second embodiment of a water electrolysis hydrogen production system provided in an embodiment of the present application;

[0060] FIG3 is a schematic diagram of a third embodiment of a water electrolysis hydrogen production system provided in an embodiment of the present application;

[0061] FIG4 is a schematic diagram of a fourth embodiment of a water electrolysis hydrogen production system provided in an embodiment of the present application;

[0062] FIG5 is a schematic structural diagram of an electrolytic cell provided in an embodiment of the present application;

[0063] FIG6 is a schematic structural diagram of a second electrode plate provided in an embodiment of the present application;

[0064] FIG7 is a schematic structural diagram of a first electrode plate provided in an embodiment of the present application under a first embodiment;

[0065] FIG8 is a schematic structural diagram of the first electrode plate provided in an embodiment of the present application under a second embodiment;

[0066] FIG9 is a schematic structural diagram of a first electrode plate according to a third embodiment of the present application;

[0067] FIG10 is a schematic structural diagram of a first electrode plate according to a fourth embodiment of the present application;

[0068] FIG11 is a schematic structural diagram of a water electrolysis hydrogen production system provided by an embodiment of the present application, wherein the electrolyzer has an oxygen side flow channel inlet and a hydrogen side flow channel inlet;

[0069] FIG12 is a schematic structural diagram of a water electrolysis hydrogen production system provided by an embodiment of the present application, wherein the electrolyzer has two oxygen side flow channel inlets and two hydrogen side flow channel inlets;

[0070] 13 is a schematic structural diagram of another water electrolysis hydrogen production system provided in an embodiment of the present application, wherein the electrolyzer has an oxygen side flow channel inlet and a hydrogen side flow channel inlet;

[0071] 14 is a schematic structural diagram of another water electrolysis hydrogen production system provided in an embodiment of the present application, wherein the electrolyzer has two oxygen side flow channel inlets and two hydrogen side flow channel inlets;

[0072] FIG15 is a flow chart of a method for controlling gas purity provided in an embodiment of the present application;

[0073] FIG16 is a flow chart of another method for controlling gas purity provided in an embodiment of the present application;

[0074] FIG17 is a schematic diagram of a computing and processing device provided in an embodiment of the present application.

[0075] Figure 1: 1-electrolyzer 2-hydrogen gas-liquid separation unit 3-oxygen gas-liquid separation unit 4-alkali liquid cooler 5-control unit 6-first flow detection component 7-second flow detection component 8-first variable frequency pump 9-second variable frequency pump 10-circulation pump 11-first regulating valve 12-second regulating valve 13-hydrogen side alkali liquid flow channel inlet 14-oxygen side alkali liquid flow channel inlet 15-hydrogen side gas outlet 16-oxygen side gas outlet 17-first hydrogen side gas outlet 18-first oxygen side gas outlet 19-hydrogen side flow channel inlet 20-oxygen side flow channel inlet 21-second hydrogen side gas outlet 22-second oxygen side gas outlet 23-second hydrogen side alkali liquid flow channel inlet 24-second Oxygen-side alkali liquid flow channel inlet 25 - first gas purity detection component 26 - second gas purity detection component 27 - oxygen outlet 28 - hydrogen outlet 29 - second valve 30 - third valve 101 - tank body 111 - first exhaust flow channel 112 - second exhaust flow channel 102 - first electrode plate 121 - first cavity 122 - second cavity 103 - second electrode plate 131 - first liquid inlet 132 - second liquid inlet 133 - first exhaust port 134 - second exhaust port 104 - first flow field structure 141 - first liquid inlet flow channel 142 - first liquid distribution flow channel 105 - second flow field structure 151 - second liquid inlet flow channel 152 - second liquid distribution flow channel

[0076] Detailed description

[0077] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0078] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0079] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0080] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on this application.

[0081] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0082] The present application provides a water electrolysis hydrogen production system, as shown in Figure 1, the system includes an electrolyzer 1, a hydrogen gas-liquid separation unit 2 and an oxygen gas-liquid separation unit 3; wherein, the liquid outlet of the hydrogen gas-liquid separation unit 2 is connected to a first pipeline, and the liquid outlet of the oxygen gas-liquid separation unit 3 is connected to a second pipeline, and the first pipeline and the second pipeline are connected to one end of an alkali liquid reflux pipeline after merging, and the other end of the alkali liquid reflux main pipeline is connected to an oxygen side pipeline and a hydrogen side pipeline in parallel; the hydrogen side pipeline is connected to the hydrogen side alkali liquid flow channel inlet 13 of the electrolyzer, and the oxygen side pipeline is connected to the oxygen side alkali liquid flow channel inlet 14 of the electrolyzer; that is, the alkali liquid reflux main pipeline is connected to the hydrogen side alkali liquid flow channel inlet 13 of the electrolyzer. The liquid reflux pipeline is the main pipeline for the alkali liquid to return from the hydrogen gas-liquid separation unit 2 and the oxygen gas-liquid separation unit 3 to the electrolyzer. The parallel oxygen-side pipeline and hydrogen-side pipeline are two branches through which the alkali liquid flows to the oxygen-side alkali liquid flow channel inlet 14 and the hydrogen-side alkali liquid flow channel inlet 13 of the electrolyzer respectively via the alkali liquid reflux pipeline; the hydrogen-side pipeline is provided with a first flow detection component 6 and a first flow regulation component; the oxygen-side pipeline is provided with a second flow detection component 7 and a second flow regulation component; the hydrogen-side gas outlet 15 of the electrolyzer is connected to the hydrogen gas-liquid separation unit 2, and the oxygen-side gas outlet 16 of the electrolyzer is connected to the oxygen gas-liquid separation unit 3. The first flow detection component 6 can be a flowmeter, and the second flow detection component 7 can be a flowmeter. The flowmeters can be independently selected from one of an area flowmeter, a volume flowmeter, a Coriolis flowmeter, and an electromagnetic flowmeter.

[0083] There are usually two ways to circulate the electrolyte. The first way is to first merge the electrolytes of the hydrogen gas-liquid separation unit 2 and the oxygen gas-liquid separation unit 3 and then return them to the electrolytic cell through the inlet at the end of the electrolytic cell, and then distribute the electrolyte to the cathode side and anode side of each electrolytic chamber at the same time. This method cannot separately control the flow field and pressure of the electrolyte on the cathode side and anode side of the electrolytic chamber, and cannot control the purity of the gas produced on both sides. Another way is to return the electrolyte in the hydrogen gas-liquid separation unit 2 to the cathode side of each chamber of the electrolytic cell, and return the electrolyte in the oxygen gas-liquid separation unit 3 to the anode side of each chamber of the electrolytic cell. This method will cause the electrolyte concentration on the cathode side and the anode side to deviate after long-term operation, so it is necessary to set up an additional electrolyte circulation box to partially exchange the electrolyte on the cathode side and the anode side.

[0084] The water electrolysis hydrogen production system of the present application can control the flow rates at the hydrogen and oxygen inlets on both sides of the electrolyzer separately, which can not only ensure that the alkali concentrations at the hydrogen and oxygen inlets on both sides of the electrolyzer remain consistent, but also provide different control options for alkali circulation strategies under different working conditions. Specifically, the present application implements fine-tuning by controlling the first flow regulating component and the second flow regulating component to achieve fine-tuning of the alkali flow rate entering the cathode side or anode side of the diaphragm of the electrolyzer chamber, thereby regulating the pressure difference between the cathode side and the anode side of each chamber, thereby slowing down the hydrogen / oxygen permeation rate, and thus improving the oxygen\hydrogen gas purity under different working conditions, especially low-load conditions.

[0085] In one embodiment of the present application, as shown in FIG1 , the water electrolysis hydrogen production system may further include a control unit 5, a first flow detection component 6 and a second flow detection component 7 are electrically connected to the control unit 5, and a first flow regulation component and a second flow regulation component are electrically connected to the control unit 5. The control unit 5 may be an existing single-chip microcomputer, a PLC controller, or the like, or may be a controller in an existing control device for controlling a hydrogen production device in a water electrolysis hydrogen production system.

[0086] In one embodiment of the present application, as shown in FIG1 , the first flow regulating component is a first variable frequency pump 8, and the control unit 5 receives a signal from the first flow detection component 6 and is signal-connected to the first variable frequency pump 8; the second flow regulating device is a second variable frequency pump 9, and the control unit 5 receives a signal from the second flow detection component 7 and is signal-connected to the second variable frequency pump 9. In this embodiment, the first variable frequency pump 8, the second variable frequency pump 9, the first flow detection component 6, and the second flow detection component are respectively electrically connected to the control unit 5. The first flow detection component 6 and the second flow detection component 7 are used to detect the electrolyte flow rate of the water electrolysis hydrogen production system and send it to the control unit 5. The input voltage, current, and gas purity data are fed back to the control unit 5, and the control unit 5 controls the rotation speed of the first variable frequency pump 8 and the second variable frequency pump 9 to adjust the flow rate on the cathode side and the anode side.

[0087] In another embodiment of the present application, as shown in FIG2 , a circulation pump 10 is provided on the main alkali liquid reflux line; the first flow regulating component includes a first regulating valve 11, and the control unit 5 is respectively connected to the first flow detection component 6 and the first regulating valve 11 for receiving the first flow signal of the first flow detection component 6 and adjusting the opening and closing of the first regulating valve 11 according to the first flow signal; the second flow regulating component is a second regulating valve 12, and the control unit 5 is respectively connected to the second flow detection component 7 and the second regulating valve 12 for receiving the second flow signal of the second flow detection component 7 and adjusting the opening and closing of the second regulating valve 12 according to the second flow signal. In this embodiment, the first regulating valve 11, the second regulating valve 12, the first flow detection component 6, and the second flow detection component 7 are respectively electrically connected to the control unit 5. The first flow detection component 6 and the second flow detection component 7 are used to detect the electrolyte flow of the water electrolysis hydrogen production system and send it to the control unit 5. The data is fed back to the control unit based on the input voltage, current, and gas purity data. The control unit 5 controls the opening of the first regulating valve 11 and the second regulating valve 12 to adjust the flow on the cathode side and the anode side. In one embodiment of the present application, the first regulating valve 11 and the second regulating valve 12 can be well-known control valves that can continuously control the valve opening. For example, the first regulating valve 11 and the second regulating valve 12 can each be independently selected from one of a ball valve, a butterfly valve, a globe valve, a needle valve, a diaphragm regulating valve and an electric regulating valve; the circulating pump 10 can be a non-positive displacement pump. For example, the circulating pump 10 can be a centrifugal pump, a turbine pump, etc.

[0088] In one embodiment of the present application, as shown in Figure 1, the water electrolysis hydrogen production system may further include an alkali liquid cooler 4; an alkali liquid cooler 4 is provided on the alkali liquid reflux main line, the alkali liquid cooler 4 includes a feed port and a discharge port, and the discharge port of the alkali liquid cooler is connected to an oxygen side pipeline and a hydrogen side pipeline in parallel. In one embodiment of the present application, the discharge port of the alkali liquid cooler 4 may be connected to the feed port of a filter, and the discharge port of the filter is connected to the feed port of the circulation pump 10. The present application filters the impurities present in the alkali liquid by providing a filter on the pipelines of the alkali liquid cooler 4 and the circulation pump 10.

[0089] In one embodiment of the present application, the hydrogen side pipeline may also be provided with a first control valve, the first control valve is used to control the circulation and cut-off of the hydrogen side pipeline, and control the single-phase flow of the liquid in the hydrogen side pipeline; the oxygen side pipeline may also be provided with a second control valve, the second control valve is used to control the circulation and cut-off of the oxygen side pipeline, and control the single-phase flow of the liquid in the oxygen side pipeline. Exemplarily, the first control valve and the second control valve can be switch valves, cut-off valves or check valves, which are used to cut off the circulation of the pipeline or control the single-phase flow of the liquid in the event of a fault, startup or shutdown. In the present application, the single-phase flow of the liquid in the hydrogen side pipeline and the single-phase flow of the liquid in the oxygen side pipeline are specifically unidirectional flows from the alkali liquid cooler to the electrolyzer.

[0090] In one embodiment of the present application, the electrolytic cell 1 may include a positive electrode and a negative electrode, and the positive electrode and the negative electrode are respectively located at the two ends of the electrolytic cell 1; wherein the negative end of the electrolytic cell 1 is provided with a hydrogen side alkali liquid flow channel inlet 13, an oxygen side alkali liquid flow channel inlet 14, a hydrogen side gas outlet 15 and an oxygen side gas outlet 16. In an exemplary embodiment of the present application, as shown in Figures 3 and 4, the electrolytic cell 1 includes a positive electrode, a first negative electrode and a second negative electrode, and the positive electrode is located in the middle of the electrolytic cell, and the first negative electrode and the second negative electrode are respectively located at the two ends of the electrolytic cell; wherein the first negative end of the electrolytic cell 1 is provided with a first hydrogen side gas outlet 17, a first oxygen side gas outlet 18, The first hydrogen side alkali liquid flow channel inlet 19 and the first oxygen side alkali liquid flow channel inlet 20, the second negative end of the electrolyzer 1 is provided with a second hydrogen side gas outlet 21, a second oxygen side gas outlet 22, a second hydrogen side alkali liquid flow channel inlet 23 and a second oxygen side alkali liquid flow channel inlet 24; the hydrogen side pipeline is connected with the first hydrogen side pipeline and the second hydrogen side pipeline in parallel, and the oxygen side pipeline is connected with the first oxygen side pipeline and the second oxygen side pipeline in parallel; the first hydrogen side gas outlet 17 and the second hydrogen side gas outlet 21 are connected to the hydrogen gas-liquid separation unit The feed inlet pipeline of element 2, the first oxygen side gas outlet 18 and the second oxygen side flow channel outlet 22 are connected to the feed inlet pipeline of the oxygen gas-liquid separation unit 3; the first hydrogen side pipeline is connected to the first hydrogen side alkali liquid flow channel inlet 19 of the electrolyzer 1, and the second hydrogen side pipeline is connected to the second hydrogen side alkali liquid flow channel inlet 23 of the electrolyzer 1; the first oxygen side pipeline is connected to the first oxygen side alkali liquid flow channel inlet 20 of the electrolyzer 1, and the second oxygen side pipeline is connected to the second oxygen side alkali liquid flow channel inlet 24 of the electrolyzer 1.

[0091] In one embodiment of the present application, the water electrolysis hydrogen production system may further include at least two electrolytic cells, and one end of the pipeline directly connecting the hydrogen side gas outlet of each electrolytic cell and the hydrogen gas-liquid separation unit 2 is connected to the feed port of the hydrogen gas-liquid separation unit 2 after being aggregated; and one end of the pipeline directly connecting the oxygen side gas outlet of each electrolytic cell and the oxygen gas-liquid separation unit 3 is connected to the feed port of the oxygen gas-liquid separation unit 3 after being aggregated.

[0092] In one embodiment of the present application, a hydrogen side gas outlet temperature detection component may be provided on the pipeline of the hydrogen side gas outlet; and / or, an oxygen side gas outlet temperature detection component may be provided on the pipeline of the oxygen side gas outlet, and the hydrogen side temperature detection component and the oxygen side temperature detection component are used to detect the temperature of the electrolytic cell; a hydrogen side alkali liquid flow channel inlet temperature detection component may be provided on the pipeline of the hydrogen side alkali liquid flow channel inlet; and / or, an oxygen side alkali liquid flow channel inlet temperature detection component may be provided on the pipeline of the oxygen side alkali liquid flow channel inlet, and the hydrogen side temperature detection component and the oxygen side temperature detection component are used to detect the temperature of the alkali liquid.

[0093] In one embodiment of the present application, the hydrogen gas-liquid separation unit 2 may further include a hydrogen side gas-liquid separator, a hydrogen side scrubber and a hydrogen side cooler, and the oxygen gas-liquid separation unit 3 may further include an oxygen side gas-liquid separator, an oxygen side scrubber and an oxygen side cooler; wherein, the gas-liquid inlet of the hydrogen side gas-liquid separator is connected to the hydrogen side gas outlet of the electrolyzer unit, the gas outlet of the hydrogen side gas-liquid separator is connected to the gas inlet of the hydrogen side scrubber, and the gas outlet of the hydrogen side scrubber is connected to the gas inlet of the hydrogen side cooler; the gas-liquid inlet of the oxygen side gas-liquid separator is connected to the oxygen side gas outlet of the electrolyzer unit, the gas outlet of the oxygen side gas-liquid separator is connected to the gas inlet of the oxygen side scrubber, and the gas outlet of the oxygen side scrubber is connected to the gas inlet of the oxygen side cooler.

[0094] In one embodiment of the present application, the hydrogen-side cooler may be connected to a hydrogen-side liquid trap, and the oxygen-side cooler may be connected to an oxygen-side liquid trap. The hydrogen-side liquid trap and the oxygen-side liquid trap of the present application can further remove water from hydrogen and oxygen.

[0095] In one embodiment of the present application, in order to recover water in the gas-liquid separation process, the hydrogen side scrubber, the hydrogen side cooler, the hydrogen side liquid collector, the oxygen side scrubber, the oxygen side cooler and the oxygen side liquid collector can be integrated, that is, the hydrogen side gas-liquid separator is further connected to the washing, cooling and water removal integrated equipment, and the oxygen side gas-liquid separator is further connected to the washing, cooling and water removal integrated equipment.

[0096] In one embodiment of the present application, the water electrolysis hydrogen production system may further include a gas purity detection component, which is electrically connected to the control unit 5 and is configured to detect the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system.

[0097] In one embodiment of the present application, the electrolytic cell includes a cell body 101, wherein a plurality of electrolytic chambers are provided in the cell body 101, each electrolytic chamber including an anode region and a cathode region. Taking a filter press bipolar electrolytic cell as an example, the cell body 101 is generally constructed of a plurality of annular pole frames, and the pole pieces in the pole frames divide the cell body 101 into a plurality of electrolytic chambers. A diaphragm is provided between two adjacent pole pieces, further dividing the electrolytic chambers into an anode region capable of producing oxygen and a cathode region capable of producing hydrogen. In order to clearly express the flow channel structure in the present application, structures such as the electrolytic chambers in the cell body are omitted. A first pole plate 102 is provided in the cell body 101, and a first cavity 121 and a second cavity 122 are formed therein.

[0098] The electrolytic cell also includes a first flow field structure 104 and a second flow field structure 105. The first flow field structure 104 includes a first liquid inlet channel 141 and a first liquid distribution channel 142 provided in the wall of the cell body 101. The first liquid distribution channel 142 is used to communicate with multiple anode regions respectively and communicate with the first liquid inlet channel 141 through the first cavity 121. The second flow field structure 105 includes a second liquid inlet channel 151 and a second liquid distribution channel 152 provided in the wall of the cell body 101. The second liquid distribution channel 152 is used to communicate with multiple cathode regions respectively and communicate with the second liquid inlet channel 151 through the second cavity 122. Here, the cell wall of the cell body 101 refers to the annular pole frame that constitutes the cell body 101.

[0099] Through the above technical solution, the first flow field structure 104 is connected to multiple anode areas through the first liquid distribution channel 142, and the second flow field structure 15 is connected to multiple cathode areas through the second liquid distribution channel 152. The operator can input electrolyte into the anode area and the cathode area respectively through the first flow field structure 104 and the second flow field structure 105. When the amount of electrolyte required in the cathode area is different from the amount of electrolyte required in the anode area, the operator can accurately input electrolyte into the anode area and the cathode area respectively. At the same time, the electrolyte input into the anode area will enter the first liquid distribution channel 142 through the first liquid inlet channel 141 and the first cavity 121, and the electrolyte input into the cathode area will enter the second liquid distribution channel 152 through the second liquid inlet channel 151 and the second cavity 122. The first liquid inlet channel 141, the first cavity 121, the second liquid inlet channel 151, and the second cavity 122 can buffer the electrolyte and reduce the temperature of the electrolytic cell, making the temperature and flow field distribution in the electrolytic cell more uniform. In this way, the electrolyte will be more stable when entering the first liquid distribution channel 142 and the second liquid distribution channel 152, avoiding the amount of electrolyte input into the anode area and the cathode area in the inlet area of ​​the first liquid distribution channel 142 and the second liquid distribution channel 152 being greater than the amount of electrolyte input into the anode area and the cathode area away from the inlet area of ​​the first liquid distribution channel 142 and the second liquid distribution channel 152, so that the operator can accurately input the electrolyte into the anode area and the cathode area.

[0100] It should be noted that the use of the electrolyzer 101 in the embodiment of the present application is not limited to the water electrolysis hydrogen production system, that is, the electrolyzer 101 in the embodiment of the present application can also be used independently without the water electrolysis hydrogen production system.

[0101] In one embodiment of the present application, the anode region and the cathode region are designed to be liquid-inlet separately, so that the content of the electrolyte in the anode region and the cathode region can be independently controlled, so that the flow field of the electrolytic cell flow channel has a certain external operability, which can expand the flexibility of the control of the flow field of the electrolytic cell flow channel, facilitate the adjustment of the operating performance of the electrolytic cell, and can also be used to improve the operating performance of the electrolytic cell and the gas purity. Taking the use of renewable energy such as wind energy to power the electrolytic cell when producing hydrogen by electrolysis of water as an example, due to environmental factors, the energy supply may fluctuate, further causing the electrolysis power of the electrolytic cell to fluctuate. For example, when the electrolysis power of the electrolytic cell fluctuates, the degree to which the hydrogen generated in the cathode region enters the anode region through the diaphragm increases, which will cause the hydrogen content in the oxygen in the anode region to increase, and when the hydrogen content in the oxygen exceeds 4%, there is a risk of explosion. When the above situation occurs, the flow rate in the first flow field structure 104 can be adjusted to increase the electrolyte input into the anode area, and at the same time, the flow rate in the second flow field structure 105 can be adjusted to reduce the electrolyte input into the cathode area, so that the pressure in the anode area and the pressure in the cathode area can be balanced to avoid gas cross-talk.

[0102] In another embodiment of the present application, the electrolytic cell may further include a second electrode plate 103, the first liquid inlet 131 of the first liquid inlet channel 141 may be provided on the second electrode plate 103, and the second liquid inlet 132 of the second liquid inlet channel 151 may be provided on the second electrode plate 103. In some embodiments, the first electrode plate 102 and the second electrode plate 103 may be provided at both ends of the cell body 101, respectively. Specifically, reference may be made to FIG5. In this case, the first liquid inlet channel 141, the first liquid distribution channel 142, the second liquid inlet channel 151 and the second liquid distribution channel 152 may extend from one end of the cell body 101 to the other end of the cell body 101, respectively. This allows the first liquid distribution channel 142 and the second liquid distribution channel 152 to flow through all the electrolysis cells. At the same time, such a design may also increase the length of the first liquid inlet channel 141 and the second liquid inlet channel 151, thereby ensuring the effectiveness of the first liquid inlet channel 141 and the second liquid inlet channel 151.

[0103] Typically, end pressure plates are provided at both ends of the trough body 101, which can make the trough body 101 more stable. When the second electrode plate 103 is provided at the end of the trough body 101, a plurality of through holes can be correspondingly opened on the end pressure plates. The plurality of through holes can respectively correspond to the first liquid inlet 131 and the second liquid inlet 132 to ensure the use of the second electrode plate 103.

[0104] By adjusting the number and arrangement of the first electrode plates 102 and the second electrode plates 103, the first flow field structure 104 and the second flow field structure 105 can also adjust the input electrolyte in different regions. In some embodiments, the second electrode plates 103 can also be symmetrically arranged on both sides of the first electrode plate 102 in the extension direction of the tank body 101 and spaced apart from the first electrode plate 102. In this way, the first flow field structure 104 and the second flow field structure 105 are respectively arranged in the areas on both sides of the first electrode plate 102, and the operator can separately adjust the electrolyte to be input in the areas on both sides of the first electrode plate 102.

[0105] In another embodiment of the present application, a plurality of first electrode plates 102 are provided on one side of the second electrode plate 103 at equal intervals along the extension direction of the tank body 101 to adjust the electrolyte input in different regions. In this way, the operator can separately adjust the electrolyte input in the region between the first electrode plate 102 and the second electrode plate 103 and the region between two adjacent second electrode plates 103.

[0106] The two aforementioned implementations of regulating the input electrolyte in different regions can prevent the extension path of the liquid distribution channel from being too long. The electrolyte input into the electrolysis chamber can cool the electrolyte already in the electrolysis chamber, preventing the temperature of the electrolytic cell from being too high. The electrolyte to be input is cooled before being input into the cell body 101. The cell body 101 also generates heat during the electrolysis operation. If the extension path of the liquid distribution channel is too long, the electrolyte in the flow field structure will heat up quickly, making it difficult to reduce the temperature of the electrolytic cell.

[0107] During the manufacturing process of the first electrode 102, the shape and volume of the first cavity 121 and the second cavity 122 can be designed according to the flow rate requirements of the electrolyte. For example, when the flow rate of the electrolyte is small, the first cavity 121 and the second cavity 122 can be set to a smaller volume. In addition, the volumes of the first cavity 121 and the second cavity 122 can be the same, so as to facilitate the preparation of the electrode and extend its service life. In this way, it can be ensured that the use effects of the first cavity 121 and the second cavity 122 are the same. When there are multiple first flow field structures 104 and the second flow field structures 105 respectively, the multiple first cavities 121 and the multiple second cavities 122 can also correspond one to one, ensuring that the volumes of the multiple first cavities 121 and the volumes of the multiple second cavities 122 are the same.

[0108] In the first embodiment of the present application, referring to FIG7 , the first cavity 121 and the second cavity 122 can be configured to extend from the bottom end to the top end of the first electrode plate 102. In the second embodiment of the present application, referring to FIG8 , the first cavity 121 and the second cavity 122 can be configured to extend from the bottom end to the middle area of ​​the first electrode plate 102. Both of the above embodiments can maximize the size of the first electrode plate 102.

[0109] In a third embodiment of the present application, referring to FIG9 , the first cavity 121 and the second cavity 122 can be configured to arch upward from the bottom of the first electrode plate 102. Compared to the first and second embodiments, the configuration of arching upward from the bottom of the first electrode plate 102 can further reduce the volume of the first cavity 121 and the second cavity 122.

[0110] In the fourth embodiment of the present application, referring to Figure 10 , the first cavity 121 and the second cavity 122 can be constructed as waist-shaped cavities. The liquid inlet channel can be directly connected to the liquid distribution channel through the waist-shaped cavity, making the volumes of the first cavity 121 and the second cavity 122 smaller.

[0111] Multiple first flow field structures 104 and second flow field structures 105 can be provided. By increasing the number of first flow field structures 104 and second flow field structures 105, operators can more accurately adjust the flow rate of electrolyte input to the anode region and cathode region, and adapt to and match the fluctuation of electrolytic power of the electrolytic cell with faster response speed.

[0112] In one embodiment of the present application, the plurality of first flow field structures 104 and the plurality of second flow field structures 105 can be arranged alternately and spaced along the circumference of the cell body 101. In this way, the plurality of first flow field structures 104 and the plurality of second flow field structures 105 can cover a wider range, while avoiding the arrangement of the plurality of first flow field structures 104 and the plurality of second flow field structures 105 being too concentrated. When the electrolyte is input, it can enter the anode area and the cathode area more evenly, and during the input process, sufficient heat exchange can be carried out with the electrolytic cell, thereby promoting uniform temperature of the entire electrolytic cell.

[0113] The diameter of the first liquid inlet channel 141 may be no smaller than the diameter of the first liquid distribution channel 142, and the diameter of the second liquid inlet channel 151 may be no smaller than the diameter of the second liquid distribution channel 152. This ensures the pressure and flow rate of the electrolyte in the first and second liquid distribution channels 142, 152, allowing the electrolyte in the first and second liquid distribution channels 142, 152 to more easily enter the anode and cathode regions, while also preventing the electrolyte in the anode and cathode regions from flowing back into the first and second liquid distribution channels 142, 152.

[0114] In one embodiment of the present application, the electrolytic cell may include a first gas outlet 133 and a second gas outlet 134, respectively disposed on the second electrode plate 103. The cell body 101 is provided with a first exhaust channel 111 capable of communicating with multiple anode regions, and a second exhaust channel 112 capable of communicating with multiple cathode regions. The first and second exhaust channels 111, 112 are capable of collecting gases generated during electrolysis. Referring to Figures 5 and 6, the first and second gas outlets 133, 134, and the first and second exhaust channels 111, 112 may be disposed in the upper half of the electrolytic cell to facilitate gas collection. Due to the characteristics of gases, gases generated in the anode and cathode regions tend to migrate upward. Correspondingly, the first and second flow field structures 104, 105 may be disposed in the lower half of the electrolytic cell. Furthermore, the first and second exhaust channels 111, 112 may be arranged in alternating intervals along the circumference of the cell body 101 to facilitate the rapid discharge of gases from the anode and cathode regions, while promoting temperature uniformity throughout the electrolytic cell.

[0115] In one embodiment of the present application, the electrolytic cell may further include a regulating component for respectively regulating the pressure, flow rate, and flow rate of the electrolyte in the first flow field structure 104 and the second flow field structure 105. The regulating component here may be a liquid pressure regulating valve and a liquid flow rate regulating valve, etc. The electrolyte first flows through the regulating components such as the pressure regulating valve and the liquid flow rate regulating valve before flowing into the first flow field structure 104 and the second flow field structure 105. The regulating component enables the operator to more accurately input the electrolyte into the anode region and the cathode region.

[0116] Figures 11 to 14 illustrate a water electrolysis hydrogen production system, which exemplarily illustrates a hydrogen production device and a gas purity control device of the present application, disposed on the hydrogen production device. The hydrogen production device includes an electrolyzer 1, an oxygen-side gas-liquid separation unit 3, a hydrogen-side gas-liquid separation unit 2, an electrolyte cooler 4, an oxygen outlet 27, a hydrogen outlet 28, a second valve 29, and a third valve 30. Among them, generally, the electrolyzer 1 will be provided with an oxygen side flow channel inlet 20 for the electrolyte to flow in, a hydrogen side flow channel inlet 19, and an oxygen side gas outlet 16 and a hydrogen side gas outlet 15 for the mixed fluid of gas (hydrogen / oxygen) and electrolyte to flow out. According to needs, the oxygen side flow channel inlet 20, the hydrogen side flow channel inlet 19, the oxygen side gas outlet 16, and the hydrogen side gas outlet 15 can be independently provided with more than one (such as 1, 2, 3, 4 or more than 5); in addition, two parallel control valves (such as a second valve 29 and a third valve 30) are generally provided on the pipeline of the oxygen outlet 27 and the pipeline of the hydrogen outlet 28 to facilitate the control of the pressure, liquid level, etc. in the oxygen side gas-liquid separation unit 3 and the hydrogen side gas-liquid separation unit 2. This hydrogen production device is merely intended to clearly illustrate the apparatus for controlling gas purity in a water electrolysis hydrogen production system of the present application. This simplified, exemplary hydrogen production device may also include structures found in existing hydrogen production devices, such as a power source for electrolysis and other structures in a gas-liquid separation unit. The incorporation of the apparatus for controlling gas purity of the present application within the hydrogen production device facilitates the description of the technical solution of the apparatus for controlling gas purity of the present application.

[0117] Specifically, after the above-mentioned gas purity detection component obtains the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system, it transmits the information to the control unit 5, so that the control unit 5 can control the electrolyte flow rate of the hydrogen side flow channel inlet 19 and the electrolyte flow rate of the oxygen side flow channel inlet 20 of the electrolyzer 1 respectively through the first variable frequency pump 8 and the second variable frequency pump 9, and detect the changes in the electrolyte flow rate of the hydrogen side flow channel inlet 19 and the oxygen side flow channel inlet 20 respectively through the first flow detection component 6 and the second flow detection component 7 to achieve precise control of the flow rate, thereby accurately controlling the pressure difference between the cathode chamber and the anode chamber, so as to achieve accurate control of the purity of the produced gas and reduce the oxygen content in the hydrogen and the hydrogen content in the oxygen.

[0118] The present application also provides a method for controlling gas purity during water electrolysis hydrogen production, comprising:

[0119] Obtaining the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the hydrogen production system;

[0120] When the hydrogen content in the oxygen is greater than a first content value, increasing the electrolyte flow rate at the oxygen-side flow channel inlet of the electrolyzer and / or decreasing the electrolyte flow rate at the hydrogen-side flow channel inlet of the electrolyzer until the hydrogen content in the oxygen is less than or equal to a first target value;

[0121] When the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is increased and / or the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is decreased until the oxygen content in the hydrogen is less than or equal to the second target value.

[0122] This embodiment provides a method for controlling gas purity during water electrolysis hydrogen production, which can achieve control of the gas purity prepared by the hydrogen production system (i.e., control of the hydrogen content in oxygen and the oxygen content in hydrogen) through the device for controlling gas purity in the above-mentioned water electrolysis hydrogen production system.

[0123] Regarding the above-mentioned "obtaining the hydrogen content in the oxygen prepared by the hydrogen production system and the oxygen content in the hydrogen", it can be achieved through the above-mentioned "gas purity detection component", and regarding increasing or decreasing the electrolyte flow rate, it can be achieved through the above-mentioned "control unit 5", "first variable frequency pump 8, second variable frequency pump 9, first regulating valve 11 and second regulating valve 12" and "first flow detection component 6 and second flow detection component 7" in cooperation.

[0124] Regarding the above-mentioned first content value, first target value, second content value, and second target value, all can be preset values. In this embodiment, preferably, the first content value is 0.5% to 1.5% by volume; the first target value is 0.5% to 1.5% by volume; the second content value is 0.5% to 1.5% by volume; and the second target value is 0.5% to 1.5% by volume. Technicians can specifically set appropriate values ​​within the above ranges as needed.

[0125] In the above method, the electrolyte flow rate at the oxygen side flow channel inlet and the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer can be adjusted according to the hydrogen content in the obtained oxygen and the oxygen content in the hydrogen, thereby regulating the pressure difference between the cathode chamber and the anode chamber to achieve the purpose of controlling the purity of the prepared gas.

[0126] In one embodiment of the present application, as shown in Figures 15 and 16, when the hydrogen content in the oxygen is greater than the first content value, the electrolyte flow rate at the oxygen-side flow channel inlet of the electrolyzer is increased and / or the electrolyte flow rate at the hydrogen-side flow channel inlet of the electrolyzer is decreased until the hydrogen content in the oxygen is less than or equal to the first target value:

[0127] When the hydrogen content in the oxygen is greater than a first content value, periodically increasing the electrolyte flow rate at the oxygen-side flow channel inlet of the electrolyzer to increase the first flow rate value and / or decreasing the electrolyte flow rate at the hydrogen-side flow channel inlet of the electrolyzer to decrease the second flow rate value at intervals of a first time value until the hydrogen content in the oxygen is less than or equal to a first target value; and / or,

[0128] When the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is increased and / or the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is decreased until the oxygen content in the hydrogen is less than or equal to the second target value:

[0129] When the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is periodically increased to a third flow rate value and / or the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is periodically decreased to a fourth flow rate value at intervals of a second time value until the oxygen content in the hydrogen is less than or equal to the second target value.

[0130] Similar to the first content value, first target value, second content value, and second target value described above, the first time value, first flow value, second flow value, second time value, third flow value, and fourth flow value can also be preset values. Furthermore, the first flow value, second flow value, third flow value, and fourth flow value can be numerical values ​​or ratios representing increases or decreases in flow compared to before the adjustment. In this embodiment, the first content value is 0.5% to 1.5% by volume; the first time value is 0.5 to 10 hours, preferably 2 to 8 hours; the first flow rate value is 0.5% to 1% of the electrolyte flow rate at the oxygen side flow channel inlet before the adjustment; the second flow rate value is 0.5% to 1% of the electrolyte flow rate at the hydrogen side flow channel inlet before the adjustment; the first target value is 0.5% to 1.5% by volume; the second content value is 0.5% to 1.5% by volume; the second time value is 0.5 to 10 hours, preferably 2 to 8 hours; the third flow rate value is 0.5% to 1% of the electrolyte flow rate at the hydrogen side flow channel inlet before the adjustment; the fourth flow rate value is 0.5% to 1% of the electrolyte flow rate at the oxygen side flow channel inlet before the adjustment; the second target value is 0.5% to 1.5% by volume, and technicians can set appropriate values ​​within the above range as needed.

[0131] Based on the previous embodiment, this embodiment further provides a more preferred method for controlling gas purity. Specifically, regarding flow rate control, changes in the electrolyte flow rate flowing into the oxygen-side flow channel inlet 211 and the hydrogen-side flow channel inlet 212 are not immediately reflected in the hydrogen content in oxygen / the oxygen content in hydrogen. Instead, changes in the hydrogen content in oxygen / the oxygen content in hydrogen have a certain hysteresis. Therefore, in this embodiment, when the hydrogen content in the oxygen is greater than the first content value / when the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate flowing into the oxygen side flow channel inlet and the hydrogen side flow channel inlet is periodically controlled, that is, after regulating a certain flow rate (first flow value / second flow value / third flow value / fourth flow value), wait for a certain time (first time value / second time value) to observe the hydrogen content in the oxygen or the oxygen content in the hydrogen. If the requirements are not met (the hydrogen content in the oxygen is less than or equal to the first target value or the oxygen content in the hydrogen is less than or equal to the second target value), the corresponding control will continue until the hydrogen content in the oxygen or the oxygen content in the hydrogen meets the requirements (the hydrogen content in the oxygen is less than or equal to the first target value or the oxygen content in the hydrogen is less than or equal to the second target value), then stop regulating and control, and stabilize production under this condition. Thus, the control of gas purity can be achieved more reliably, accurately, and safely, preventing excessive regulation from causing production suspension or safety accidents.

[0132] Regarding regulating the hydrogen content in oxygen or the oxygen content in hydrogen, it is possible to regulate the electrolyte flow rate at the hydrogen-side flow channel inlet or the electrolyte flow rate at the oxygen-side flow channel inlet, or to regulate both simultaneously. The latter generally involves a smaller adjustment range for each adjustment than the former.

[0133] As shown in Figure 15, a scheme for regulating only the electrolyte flow rate at the hydrogen side flow channel inlet or the electrolyte flow rate at the oxygen side flow channel inlet is given: the oxygen content in the hydrogen and the hydrogen content in the oxygen prepared by the hydrogen production system are obtained, and when the hydrogen content in the oxygen is greater than the first content value, the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is periodically increased at intervals of a first time value to increase the first flow value until the hydrogen content in the oxygen is less than or equal to the first target value, and then the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is locked for operation; when the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is periodically increased at intervals of a second time value to increase the third flow value until the oxygen content in the hydrogen is less than or equal to the second target value, and then the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is locked for operation.

[0134] As shown in FIG16 , a scheme for simultaneously regulating the electrolyte flow rate at the hydrogen side flow channel inlet and the electrolyte flow rate at the oxygen side flow channel inlet is provided: the oxygen content in the hydrogen produced by the hydrogen production system and the hydrogen content in the oxygen are obtained. When the hydrogen content in the oxygen is greater than a first content value, the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is periodically increased at intervals of a first time value to increase the first flow value, and the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is reduced to reduce the second flow value until the hydrogen content in the oxygen is less than or equal to the first target value. value (, and then lock the electrolyte flow rates at the hydrogen side flow channel inlet and the oxygen side flow channel inlet of the electrolyzer for operation; when the oxygen content in the hydrogen is greater than the second content value, periodically increase the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer at intervals of a second time value to increase the third flow rate value, and decrease the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer to reduce the fourth flow rate value, until the oxygen content in the hydrogen is less than or equal to the second target value, and then lock the electrolyte flow rates at the hydrogen side flow channel inlet and the oxygen side flow channel inlet of the electrolyzer for operation.

[0135] The present application also provides a device for controlling gas purity in a water electrolysis hydrogen production system, comprising: a controller unit, a gas purity detection component, a flow detection component and a flow regulation component; wherein the controller unit is configured to determine the adjustment values ​​of the electrolyte flow rate at the oxygen side flow channel inlet and the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer based on the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system, as well as the electrolyte flow rate at the oxygen side flow channel inlet and the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer; the gas purity detection component is electrically connected to the controller unit and is configured to detect the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system; the flow detection component is electrically connected to the controller unit and is configured to respectively detect the electrolyte flow rate at the oxygen side flow channel inlet and the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer; the flow control component is electrically connected to the controller unit and is configured to respectively adjust the electrolyte flow rate at the oxygen side flow channel inlet and the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer.

[0136] In one embodiment of the present application, as shown in Figures 11 to 14, the gas purity detection component includes: a first gas purity detection component 25 and a second gas purity detection component 26; the first gas purity detection component 25 is electrically connected to the controller unit and can detect the hydrogen content in the oxygen produced by the water electrolysis hydrogen production system; the second gas purity detection component 26 is electrically connected to the controller unit and can detect the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system. This application provides a specific structure of the gas purity detection component, that is, the first gas purity detection component 25 and the second gas purity detection component 26 are used to detect the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system respectively.

[0137] The present application does not specifically limit the first gas purity detection component 25 and the second gas purity detection component 26, as long as they are capable of respectively detecting the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system. In this embodiment, the first gas purity detection component 25 is a gas analyzer comprising an electrochemical sensor unit or a thermal conductivity sensor unit and configured to detect trace hydrogen content in oxygen, while the second gas purity detection component 26 is a gas analyzer comprising an electrochemical sensor unit or a thermal conductivity sensor unit and configured to detect trace oxygen content in hydrogen.

[0138] 17 , the present application further provides a computing and processing device 1000 comprising: a memory 1020 and one or more processors 1010, wherein the memory 1020 stores computer-readable code. When the computer-readable code is executed by the one or more processors 1010, the computing and processing device 1000 executes a method for controlling gas purity during water electrolysis hydrogen production as in any of the aforementioned embodiments.

[0139] The memory 1020 may include a volatile memory 1020 or a non-volatile memory 1020, or the memory 1020 may include both volatile and non-volatile memories 1020. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM) and direct RAM bus random access memory (DRRAM). The memory in the embodiments of the present application includes but is not limited to these and any other suitable types of memory.

[0140] The memory 1020 has a storage space 1030 for computer-readable code 1031 for executing any of the method steps described above. The computer-readable code 1031 can be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, compact disks (CDs), memory cards, or floppy disks.

[0141] Processor 1010 may include one or more processing units 1011. Optionally, processor 1010 integrates an application processor and a modem processor. The application processor primarily handles operations related to the operating system, user interface, and application programs, while the modem processor primarily processes wireless communication signals, such as a baseband processor. The modem processor may not be integrated into processor 1010.

[0142] The present application also provides a computer program product, including computer-readable code. When the computer-readable code runs on the computing and processing device 1000, it causes the computing and processing device 1000 to execute the method for controlling gas purity in the process of water electrolysis to produce hydrogen according to any of the aforementioned embodiments. To avoid repetition, it will not be described here.

[0143] The present application also provides a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by the processor 1010, implements the steps of the method described in any of the aforementioned embodiments. To avoid repetition, they are not described again here.

[0144] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A water electrolysis hydrogen production system, wherein: The system includes an electrolyzer, a hydrogen gas-liquid separation unit and an oxygen gas-liquid separation unit; The liquid outlet of the hydrogen gas-liquid separation unit is connected to the first pipeline, the liquid outlet of the oxygen gas-liquid separation unit is connected to the second pipeline, the first pipeline and the second pipeline are connected to one end of the alkali solution reflux main pipeline after merging, and the other end of the alkali solution reflux main pipeline is connected to the oxygen side pipeline and the hydrogen side pipeline in parallel; the hydrogen side pipeline is connected to the hydrogen side alkali solution flow channel inlet of the electrolyzer, and the oxygen side pipeline is connected to the oxygen side alkali solution flow channel inlet of the electrolyzer; the hydrogen side pipeline is provided with a first flow detection component and a first flow regulation component; the oxygen side pipeline is provided with a second flow detection component and a second flow regulation component; The hydrogen-side gas outlet of the electrolyzer is connected to the hydrogen gas-liquid separation unit, and the oxygen-side gas outlet of the electrolyzer is connected to the oxygen gas-liquid separation unit.

2. The water electrolysis hydrogen production system according to claim 1, wherein: The system further comprises a control unit, the first flow detection component and the second flow detection component are electrically connected to the control unit respectively, and the first flow regulating component and the second flow regulating component are electrically connected to the control unit respectively.

3. The water electrolysis hydrogen production system according to claim 2, wherein: The first flow regulating component includes a first variable frequency pump, and the second flow regulating component includes a second variable frequency pump.

4. The water electrolysis hydrogen production system according to claim 2, wherein: An alkali solution circulation pump is arranged on the alkali solution reflux main line, the first flow regulating component comprises a first regulating valve, and the second flow regulating component comprises a second regulating valve.

5. The water electrolysis hydrogen production system according to claim 2, wherein: The system further comprises an alkali liquid cooler, and the alkali liquid cooler is arranged on the alkali liquid reflux main line.

6. The water electrolysis hydrogen production system according to claim 1, wherein: The hydrogen side pipeline is also provided with a first control valve, which is used to control the circulation and cutoff of the hydrogen side pipeline and control the single-phase flow of the liquid in the hydrogen side pipeline; the oxygen side pipeline is also provided with a second control valve, which is used to control the circulation and cutoff of the oxygen side pipeline and control the single-phase flow of the liquid in the oxygen side pipeline.

7. The water electrolysis hydrogen production system according to claim 1, wherein: The electrolytic cell comprises a positive electrode, a first negative electrode and a second negative electrode. The positive electrode is located in the middle of the electrolytic cell, and the first negative electrode and the second negative electrode are respectively located at two ends of the electrolytic cell.

8. The water electrolysis hydrogen production system according to claim 1, wherein: The system comprises at least two electrolytic cells, The hydrogen-side gas outlet of each of the electrolyzers is connected to the feed inlet of the hydrogen gas-liquid separation unit; The oxygen-side gas outlet of each electrolytic cell is connected to the feed inlet of the oxygen gas-liquid separation unit.

9. The water electrolysis hydrogen production system according to any one of claims 1 to 8, wherein: The system further comprises: A gas purity detection component is electrically connected to the control unit and is capable of detecting the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system.

10. The water electrolysis hydrogen production system according to claim 1, wherein: The electrolytic cell comprises: A tank body, wherein a plurality of electrolytic chambers are arranged in the tank body, each of the electrolytic chambers comprises an anode region and a cathode region, a first electrode plate is arranged in the tank body, and a first cavity and a second cavity are formed in the first electrode plate; a first flow field structure, comprising a first liquid inlet channel and a first liquid distribution channel disposed in the tank wall of the tank body, wherein the first liquid distribution channel is used to communicate with the plurality of anode regions respectively and communicate with the first liquid inlet channel through the first cavity; and The second flow field structure includes a second liquid inlet channel and a second liquid distribution channel arranged in the groove wall of the groove body, and the second liquid distribution channel is used to communicate with the multiple cathode areas respectively and communicate with the second liquid inlet channel through the second cavity.

11. The water electrolysis hydrogen production system according to claim 10, wherein: The electrolytic cell also includes a second electrode plate, which is symmetrically arranged on both sides of the first electrode plate in the extension direction of the cell body and spaced apart from the second electrode plate, and the first liquid inlet of the first liquid inlet channel and the second liquid inlet of the second liquid inlet channel are both arranged on the second electrode plate.

12. The water electrolysis hydrogen production system according to claim 10, wherein: The electrolytic cell also includes a second electrode plate, a plurality of first electrode plates are arranged at equal intervals on one side of the second electrode plate along the extension direction of the cell body, and the first liquid inlet of the first liquid inlet channel and the second liquid inlet of the second liquid inlet channel are both arranged on the second electrode plate.

13. The water electrolysis hydrogen production system according to claim 10, wherein: A plurality of the first flow field structures and a plurality of the second flow field structures are provided respectively.

14. The water electrolysis hydrogen production system according to claim 13, wherein: A plurality of the first flow field structures and a plurality of the second flow field structures are alternately arranged along the circumference of the slot body.

15. The water electrolysis hydrogen production system according to claim 10, wherein: The first cavity and the second cavity have the same volume.

16. A method for controlling gas purity in a process of producing hydrogen by water electrolysis, the method comprising: Obtaining the hydrogen content in the oxygen produced by the hydrogen production system and the oxygen content in the hydrogen; When the hydrogen content in the oxygen is greater than the first content value, increasing the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer and / or decreasing the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer until the hydrogen content in the oxygen is less than or equal to the first target value; When the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is increased and / or the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is decreased until the oxygen content in the hydrogen is less than or equal to the second target value.

17. The method according to claim 16, wherein: When the hydrogen content in the oxygen is greater than the first content value, the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is increased and / or the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is decreased until the hydrogen content in the oxygen is less than or equal to the first target value: When the hydrogen content in the oxygen is greater than the first content value, the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is periodically increased at intervals of the first time value to increase the first flow rate value and / or the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is decreased to reduce the second flow rate value until the hydrogen content in the oxygen is less than or equal to the first target value; and / or, When the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is increased and / or the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is decreased until the oxygen content in the hydrogen is less than or equal to the second target value: When the oxygen content in the hydrogen is greater than the second content value, the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer is periodically increased to a third flow rate value and / or the electrolyte flow rate at the oxygen side flow channel inlet of the electrolyzer is periodically decreased to a fourth flow rate value at intervals of a second time value until the oxygen content in the hydrogen is less than or equal to the second target value.

18. The method according to claim 16, wherein: The first content value is 0.5% to 1.5% by volume; and / or, The first time value is 0.5 to 10 hours, preferably 2 to 8 hours; and / or, The first flow value is 0.5% to 1% of the electrolyte flow at the inlet of the oxygen side flow channel before the adjustment; and / or, The second flow value is 0.5% to 1% of the electrolyte flow at the hydrogen side flow channel inlet before the adjustment; and / or, The first target value is 0.5% to 1.5% by volume; and / or, The second content value is 0.5% to 1.5% by volume; and / or, The second time value is 0.5 to 10 hours, preferably 2 to 8 hours; and / or, The third flow value is 0.5% to 1% of the electrolyte flow at the hydrogen side flow channel inlet before the adjustment; and / or, The fourth flow value is 0.5% to 1% of the electrolyte flow at the inlet of the oxygen side flow channel before the adjustment; and / or, The second target value is 0.5% to 1.5% by volume.

19. A device for controlling gas purity in a water electrolysis hydrogen production system, comprising: The controller unit is configured to determine the adjustment values ​​of the electrolyte flow rate at the oxygen side flow channel inlet and the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer according to the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system, and the electrolyte flow rate at the oxygen side flow channel inlet and the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer; a gas purity detection component, the gas purity detection component being electrically connected to the controller unit and configured to detect the hydrogen content in the oxygen and the oxygen content in the hydrogen produced by the water electrolysis hydrogen production system; A flow detection component, the flow detection component is electrically connected to the controller unit and is configured to respectively detect the electrolyte flow rate at the oxygen side flow channel inlet and the electrolyte flow rate at the hydrogen side flow channel inlet of the electrolyzer; and, A flow regulating component is electrically connected to the controller unit and is configured to separately regulate the electrolyte flow rates at the oxygen side flow channel inlet and the electrolyte flow rates at the hydrogen side flow channel inlet of the electrolyzer.

20. A computing device, comprising: a memory having computer readable code stored therein; One or more processors, when the computer readable code is executed by the one or more processors, the computing processing device performs the water electrolysis hydrogen production process according to any one of claims 16 to 18. Method for controlling gas purity during the process.

21. A computer program product, comprising computer readable codes, which, when executed on a computing and processing device, cause the computing and processing device to execute the method for controlling gas purity in a process for producing hydrogen by water electrolysis according to any one of claims 16 to 18.

22. A computer-readable storage medium having a computer program stored thereon, wherein: When the program is executed by a processor, the steps of the method described in any one of claims 16 to 18 are implemented.

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