Water electrolysis hydrogen production system

Abstract

The utility model provides a water electrolysis hydrogen production system, which is characterized in that a pressure control unit is arranged on an original water electrolysis hydrogen production device, a safety valve is respectively arranged on a hydrogen discharge pipeline and an oxygen discharge pipeline, and the pressure control unit is provided with a hydrogen emptying pipeline, an oxygen emptying pipeline, a differential pressure gauge and a controller. The pressure difference in the hydrogen discharging pipeline, the oxygen discharging pipeline, the hydrogen emptying pipeline and the oxygen emptying pipeline is monitored in real time through the pressure difference gauge, and when the hydrogen side safety valve or the oxygen side safety valve jumps off or the pressure difference in the hydrogen discharging pipeline or the oxygen discharging pipeline exceeds a set value, the hydrogen discharging pipeline or the oxygen discharging pipeline is opened. The pressure difference of the hydrogen side or the oxygen side is quickly recovered by opening the hydrogen emptying pipeline or the oxygen emptying pipeline, and the risk of hydrogen and oxygen blow-by caused by the too large pressure difference is avoided as much as possible. The mode of combining instrument control and the safety valve is adopted, the instrument control safety level is reduced, change of an original device is small, and the technological process under the normal working condition is not affected.

Description

Technical Field

[0001] This utility model belongs to the field of water electrolysis hydrogen production technology, and specifically relates to a water electrolysis hydrogen production system. Background Technology

[0002] In existing water electrolysis hydrogen production units on the market, the cathode and anode of the electrolyzer output hydrogen and oxygen, respectively, which are then sent to separation systems for separation, washing, and cooling. Both the hydrogen-side and oxygen-side separation systems are independent pressure systems, typically without safety valves, relying solely on instrumentation for pressure interlocking protection. This control approach leads to high reliability requirements for related interlocking instruments in applications requiring adherence to petrochemical standards, and may necessitate the configuration of additional independent safety interlocking systems (SIS) depending on the project, ultimately resulting in a significant increase in unit investment costs.

[0003] Furthermore, the water electrolysis hydrogen production device using an alkaline tank has a connecting pipeline between the gas-liquid separator in the hydrogen-side separation unit and the gas-liquid separator in the oxygen-side separation unit. The connecting pipeline connects the electrolytes of the hydrogen-side gas-liquid separator and the oxygen-side gas-liquid separator, and the pressure difference balance between the two sides is maintained by the liquid level change, and the hydrogen and oxygen are isolated.

[0004] However, when an emergency release occurs on the hydrogen or oxygen side, the pressure difference between the two sides increases, which can easily lead to hydrogen and oxygen mixing and causing a fire or explosion. Utility Model Content

[0005] To address the issues of high reliability and cost associated with current water electrolysis hydrogen production units that rely on instrument pressure interlock protection, as well as the risk of fire and explosion due to hydrogen-oxygen cross-contamination, this invention provides a water electrolysis hydrogen production system. This system incorporates a pressure control unit within the existing water electrolysis hydrogen production unit, with safety valves installed on both the hydrogen and oxygen emission lines. The pressure control unit includes hydrogen vent lines, oxygen vent lines, a differential pressure gauge, and a controller. The differential pressure gauge monitors the pressure difference in the hydrogen, oxygen, and hydrogen / oxygen emission lines in real time. When the safety valve on the hydrogen or oxygen side trips, or when the pressure difference in the hydrogen or oxygen emission line exceeds a set value, the system opens the hydrogen or oxygen vent line to quickly restore the pressure difference on either side, minimizing the risk of hydrogen-oxygen cross-contamination caused by excessive pressure difference. This invention combines instrument control and safety valves, reducing the safety level of instrument control while minimizing changes to the original unit and having no impact on the process flow under normal operating conditions.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A water electrolysis hydrogen production system includes: an electrolyzer, a hydrogen-side gas-liquid separation unit, an oxygen-side gas-liquid separation unit, a hydrogen discharge pipeline, an oxygen discharge pipeline, and a pressure control unit; the electrolyzer has a cathode hydrogen outlet and an anode oxygen outlet; the hydrogen-side gas-liquid separation unit includes a hydrogen-liquid separator, which has a first inlet and a hydrogen outlet; the first inlet is connected to the cathode hydrogen outlet, and the hydrogen outlet is connected to the inlet of the hydrogen discharge pipeline; the oxygen-side gas-liquid separation unit includes an oxygen-liquid separator, which has a second inlet and an oxygen outlet; the second inlet is connected to the anode oxygen outlet, and the oxygen outlet is connected to the inlet of the oxygen discharge pipeline; the hydrogen discharge pipeline and the oxygen discharge pipeline are branched... The system includes separate hydrogen outlet regulating valves and oxygen outlet regulating valves. The pressure control unit comprises a hydrogen venting line, an oxygen venting line, a differential pressure gauge, and a controller. The inlet of the hydrogen venting line is located on the pipeline between the hydrogen outlet and the hydrogen outlet regulating valve. The inlet of the oxygen venting line is located on the pipeline between the oxygen outlet and the oxygen outlet regulating valve. The differential pressure gauge is connected to the hydrogen venting line, the oxygen venting line, the hydrogen venting line, and the oxygen venting line respectively, and is used to detect the pressure difference within each of these lines. The controller is electrically connected to the differential pressure gauge, the hydrogen outlet regulating valve, and the oxygen outlet regulating valve respectively.

[0008] In some embodiments, the hydrogen emission pipeline and the oxygen emission pipeline are respectively equipped with a hydrogen safety valve and an oxygen safety valve. The hydrogen safety valve is located on the pipeline between the inlet of the hydrogen emission pipeline and the hydrogen outlet regulating valve; the oxygen safety valve is located on the pipeline between the inlet of the oxygen emission pipeline and the oxygen outlet regulating valve.

[0009] In some embodiments, a hydrogen venting valve is provided on the hydrogen venting pipeline, and an oxygen venting valve is provided on the oxygen venting pipeline; the hydrogen venting valve and the oxygen venting valve are respectively electrically connected to the controller.

[0010] In some embodiments, the hydrogen-side gas-liquid separation unit further includes a hydrogen scrubber, the inlet of which is connected to the hydrogen outlet, and the outlet of which is connected to the inlet of the hydrogen emission pipeline; the oxygen-side gas-liquid separation unit further includes an oxygen scrubber, the inlet of which is connected to the oxygen outlet, and the outlet of which is connected to the inlet of the oxygen emission pipeline.

[0011] In some embodiments, the hydrogen-side gas-liquid separation unit further includes a hydrogen condenser, the inlet of which is connected to the outlet of the hydrogen scrubber, and the outlet of which is connected to the inlet of the hydrogen emission pipeline; the oxygen-side gas-liquid separation unit further includes an oxygen condenser, the inlet of which is connected to the outlet of the oxygen scrubber, and the outlet of which is connected to the inlet of the hydrogen emission pipeline.

[0012] In some embodiments, the water electrolysis hydrogen production system further includes a raw water supply pipeline connected to the hydrogen scrubber and the oxygen scrubber, respectively, for supplying the raw water required for the scrubbing gas to the hydrogen scrubber and the oxygen scrubber, respectively.

[0013] In some embodiments, the hydrogen liquid separator is provided with a first liquid outlet, and the oxygen liquid separator is provided with a second liquid outlet; the water electrolysis hydrogen production system further includes: a pressure balancing pipeline, the two ends of which are respectively connected to the first liquid outlet and the second liquid outlet, for balancing the pressure in the hydrogen liquid separator and the oxygen liquid separator.

[0014] In some embodiments, the hydrogen emission line and the oxygen emission line are respectively equipped with a hydrogen filter and an oxygen filter.

[0015] In some embodiments, the hydrogen liquid separator is further provided with a first electrolyte outlet, and the oxygen liquid separator is further provided with a second electrolyte outlet; the water electrolysis hydrogen production system further includes: an electrolyte recovery storage tank, which is connected to the first electrolyte outlet and the second electrolyte outlet respectively, for recovering the electrolyte separated in the hydrogen liquid separator and the oxygen liquid separator.

[0016] In some embodiments, the electrolyzer is an alkaline electrolyzer or a proton exchange membrane electrolyzer.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The water electrolysis hydrogen production system provided by this utility model is equipped with a safety valve on both the hydrogen and oxygen emission pipelines. A pressure control unit is installed on the original water electrolysis hydrogen production device. The differential pressure gauge monitors the pressure difference in the hydrogen emission pipeline, oxygen emission pipeline, hydrogen vent pipeline, and oxygen vent pipeline in real time. When the hydrogen-side safety valve or oxygen-side safety valve trips, or when the pressure difference in the hydrogen emission pipeline or oxygen emission pipeline exceeds the set parameter, the controller controls the hydrogen vent valve or oxygen vent valve to open, thereby controlling the hydrogen vent pipeline or oxygen vent pipeline to release hydrogen or oxygen to the outside, quickly restoring the pressure difference on the hydrogen side or oxygen side, and minimizing the risk of hydrogen-oxygen crosstalk caused by excessive pressure difference.

[0019] This invention combines instrument control and safety valves, reducing the safety level of instrument control, lowering instrument configuration requirements and reliability requirements for related control logic, and minimizing changes to the original equipment. Only a few interlocking loops are needed to improve system safety, with no impact on the process flow under normal operating conditions. The pressure control unit provided by this invention is also applicable to the separation system of the hydrogen-oxygen side in a PEM cell water electrolysis unit operating under unequal pressure. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 A schematic diagram of the water electrolysis hydrogen production system provided by this utility model.

[0022] The meanings of the symbols in the attached diagram are as follows:

[0023] 1—Electrolytic cell; 101—Cathode hydrogen outlet; 102—Anode oxygen outlet;

[0024] 2—Hydrogen liquid separator; 201—First gas inlet; 202—Hydrogen outlet;

[0025] 3—Oxygen-liquid separator; 301—Second air inlet; 302—Oxygen outlet;

[0026] 4—Hydrogen scrubber;

[0027] 5—Oxygen scrubber;

[0028] 6—Hydrogen emission pipeline; 601—Hydrogen outlet regulating valve; 602—Hydrogen safety valve;

[0029] 7—Oxygen discharge pipeline; 701—Oxygen outlet regulating valve; 702—Oxygen safety valve;

[0030] 8—Hydrogen venting line; 801—Hydrogen venting valve;

[0031] 9—Oxygen venting line; 901—Oxygen venting valve

[0032] 10—Differential pressure gauge;

[0033] 11—Raw water supply pipeline;

[0034] 12—Pressure balancing pipeline. Detailed Implementation

[0035] The present invention will be further explained in detail below with reference to the accompanying drawings and specific embodiments. However, the following description of the embodiments is only intended to enable those skilled in the art to better understand the principles and essence of the present invention, and does not imply any limitation on the present invention.

[0036] like Figure 1 As shown, this utility model provides a water electrolysis hydrogen production system, including: an electrolyzer 1, a hydrogen-side gas-liquid separation unit, an oxygen-side gas-liquid separation unit, a hydrogen emission pipeline 6, an oxygen emission pipeline 7, and a pressure control unit.

[0037] Specifically, the electrolytic cell 1 is equipped with a cathode hydrogen outlet 101 and an anode oxygen outlet 102.

[0038] The electrolyte enters electrolytic cell 1, where water begins to decompose under the influence of direct current. Hydrogen and oxygen are released onto the electrode surfaces of the electrolysis chamber within electrolytic cell 1. These hydrogen and oxygen gases flow out along with the electrolyte from the outlets at both ends of electrolytic cell 1 and enter the gas-liquid separation device. The temperature of electrolytic cell 1 is monitored separately on the oxygen side and the hydrogen side.

[0039] The reaction equations within electrolytic cell 1 are as follows:

[0040] Cathode: 2H₂O + 2e⁻ → H₂ + 2OH⁻ - ;

[0041] Anode: 2OH- 2e → H2O + 1 / 2O2;

[0042] Overall reaction: 2H₂O → 2H₂↑ + O₂;

[0043] Hydrogen is discharged from the cathode hydrogen outlet 101, and oxygen is discharged from the anode oxygen outlet 102.

[0044] Hydrogen outlet regulating valve 601 and oxygen outlet regulating valve 701 are respectively installed on hydrogen outlet pipeline 6 and oxygen outlet pipeline 7.

[0045] The hydrogen-side gas-liquid separation unit includes a hydrogen-liquid separator 4, which has a first inlet 201, a hydrogen outlet 202, and a first electrolyte outlet. The first inlet 201 is connected to the cathode hydrogen outlet 101, and the hydrogen outlet 202 is connected to the inlet of the hydrogen emission pipeline 6.

[0046] Hydrogen gas containing electrolyte generated by water electrolysis in electrolytic cell 1 is discharged from cathode hydrogen outlet 101 and enters hydrogen-liquid separator 2 through first inlet 201. Hydrogen-liquid separator 2 separates hydrogen gas from electrolyte. The separated hydrogen gas enters hydrogen discharge pipeline 6 from hydrogen outlet 202 and is sent to subsequent hydrogen-using devices, while the separated electrolyte is discharged from first electrolyte outlet hydrogen-liquid separator 4.

[0047] The oxygen-side gas-liquid separation unit includes an oxygen-liquid separator 3, which has a second air inlet 301, an oxygen outlet 302, and a second electrolyte outlet. The second air inlet 301 is connected to the anode oxygen outlet 102, and the oxygen outlet 302 is connected to the inlet of the oxygen discharge pipeline 7.

[0048] The oxygen entrained by the electrolyte generated by water electrolysis in the electrolytic cell 1 is discharged from the anode oxygen outlet 102 and enters the oxygen-liquid separator 3 through the second air inlet 301. The oxygen-liquid separator 3 separates the oxygen from the electrolyte. The separated oxygen enters the oxygen discharge pipeline 7 from the oxygen outlet 302 and is sent to the subsequent oxygen-using device, while the separated electrolyte is discharged from the oxygen-liquid separator 3 from the second electrolyte outlet.

[0049] The pressure control unit includes a hydrogen vent line 8, an oxygen vent line 9, a differential pressure gauge 10, and a controller. The inlet of the hydrogen vent line 8 is located on the pipeline between the hydrogen outlet 202 and the hydrogen outlet regulating valve 601; the inlet of the oxygen vent line 9 is located on the pipeline between the oxygen outlet 302 and the oxygen outlet regulating valve 701.

[0050] Differential pressure gauge 10 is connected to hydrogen emission line 6, oxygen emission line 7, hydrogen vent line 8, and oxygen vent line 9 respectively, and is used to detect the pressure difference in hydrogen emission line 6, oxygen emission line 7, hydrogen vent line 8, and oxygen vent line 9 respectively. The aforementioned differential pressure gauge 10 is preferably a PDT remote differential pressure gauge.

[0051] The controller is electrically connected to differential pressure gauge 10, hydrogen outlet regulating valve 601, and oxygen outlet regulating valve 701, respectively. Differential pressure gauge 10 collects the pressure difference in hydrogen discharge line 6, oxygen discharge line 7, hydrogen vent line 8, and oxygen vent line 9, respectively, and transmits the pressure difference value to the controller. The controller controls the opening and closing of hydrogen outlet regulating valve 601 and oxygen outlet regulating valve 701 and their opening degree according to the change of pressure difference value.

[0052] In some embodiments, a hydrogen venting valve 801 is provided on the hydrogen venting pipeline 8, and an oxygen venting valve 901 is provided on the oxygen venting pipeline 9. The hydrogen venting valve 801 and the oxygen venting valve 901 are electrically connected to a controller, and the controller controls the opening and closing of the hydrogen venting valve 801 and the degree of opening of the oxygen venting valve 901.

[0053] In some embodiments, hydrogen emission line 6 and oxygen emission line 7 are respectively provided with hydrogen safety valve 602 and oxygen safety valve 701. Hydrogen safety valve 602 is installed on the pipeline between the inlet of hydrogen emission line 6 and hydrogen outlet regulating valve 601, and oxygen safety valve 702 is installed on the pipeline between the inlet of oxygen emission line 7 and oxygen outlet regulating valve 701.

[0054] Preferably, the hydrogen safety valve 602 is designed to automatically release pressure when the pressure in the hydrogen discharge pipeline 6 exceeds the set pressure. The oxygen safety valve 702 has the same function as the hydrogen safety valve 602, and will not be described in detail here.

[0055] Furthermore, the hydrogen safety valve 602 and the oxygen safety valve 702 are electrically connected to the controller.

[0056] In some embodiments, the hydrogen-side gas-liquid separation unit further includes a hydrogen scrubber 4, the inlet of which is connected to the hydrogen outlet 202, and the outlet of which is connected to the inlet of the hydrogen emission pipeline 6. The hydrogen separated in the hydrogen-liquid separator 2 enters the hydrogen scrubber 4 from the hydrogen outlet 202, and is then sent to the hydrogen emission pipeline 6 after being scrubbed.

[0057] The oxygen-side gas-liquid separation unit also includes an oxygen scrubber 5. The inlet of the oxygen scrubber 5 is connected to the oxygen outlet 302, and the outlet of the oxygen scrubber 5 is connected to the inlet of the oxygen discharge pipeline 7. The oxygen separated in the oxygen separator 3 enters the oxygen scrubber 5 from the oxygen outlet 302 and is then sent to the oxygen discharge pipeline 7 after being scrubbed.

[0058] In some embodiments, the hydrogen-side gas-liquid separation unit further includes a hydrogen condenser. The inlet of the hydrogen condenser is connected to the outlet of the hydrogen scrubber 4, and the outlet of the hydrogen condenser is connected to the inlet of the hydrogen discharge pipeline 6. The washed hydrogen enters the hydrogen condenser, is condensed, and then discharged into the hydrogen discharge pipeline 6.

[0059] The oxygen-side gas-liquid separation unit also includes an oxygen condenser. The inlet of the oxygen condenser is connected to the outlet of the oxygen scrubber 5, and the outlet of the oxygen condenser is connected to the inlet of the oxygen discharge pipeline 7. The scrubbed oxygen enters the oxygen condenser, is condensed, and then discharged into the oxygen discharge pipeline 7.

[0060] In summary, the hydrogen side of electrolyzer 1 consists of: a cathode hydrogen outlet 101, a hydrogen-liquid separator 2, a hydrogen scrubber 4, a hydrogen condenser, and a hydrogen discharge pipeline 6 connected in sequence. The hydrogen gas containing electrolyte generated by water electrolysis is discharged into the hydrogen discharge pipeline 6 after being separated by gas and liquid, scrubbed, and condensed in sequence.

[0061] The oxygen side of electrolytic cell 1 consists of an anode oxygen outlet 102, an oxygen-liquid separator 3, an oxygen scrubber 5, an oxygen condenser, and an oxygen discharge pipeline 7 connected in sequence. The oxygen generated by water electrolysis, which carries electrolyte, is discharged into the oxygen discharge pipeline 7 after being separated by gas and liquid, washed, and condensed in sequence.

[0062] In some embodiments, the hydrogen-liquid separator 2 is provided with a first liquid outlet, and the oxygen-liquid separator 3 is provided with a second liquid outlet. The system also includes a pressure balancing pipeline 12, the two ends of which are respectively connected to the first liquid outlet and the second liquid outlet, for balancing the pressure in the hydrogen-liquid separator 2 and the oxygen-liquid separator 3.

[0063] The electrolyte in hydrogen liquid separator 2 and the electrolyte in oxygen liquid separator 3 are connected through pressure balancing pipeline 12 to maintain pressure balance in hydrogen liquid separator 2 and oxygen liquid separator 3.

[0064] Although the pressure balancing pipeline 12 can balance the pressure to a certain extent, when there is a pressure deviation between the hydrogen side and the oxygen side of the electrolyzer 1, such as when the hydrogen discharge pipeline 6 or the oxygen discharge pipeline 7 is released in an emergency, the pressure difference between the two pipelines changes, and the pressure difference between the hydrogen liquid separator 2 and the oxygen liquid separator 3 also changes. Since the pressure balancing pipeline 12 connects the hydrogen liquid separator 2 and the oxygen liquid separator 3, it is very easy for hydrogen and oxygen to cross-contaminate, which may lead to a fire and explosion risk.

[0065] This invention provides a hydrogen safety valve 602 and an oxygen safety valve 702 on the hydrogen discharge pipeline 6 and the oxygen discharge pipeline 7, respectively, which automatically activate to release pressure when the pressure in the hydrogen discharge pipeline 6 and the oxygen discharge pipeline 7 is too high.

[0066] Furthermore, considering that the pressure difference between the hydrogen and oxygen sides of electrolyzer 1 cannot be controlled when the safety valve trips or the outlet regulating valve malfunctions, such as when there is a deviation in the pressure difference between hydrogen discharge pipeline 6 and oxygen discharge pipeline 7, or a deviation in the pressure difference between hydrogen liquid separator 2 and oxygen liquid separator 3, which could easily lead to a hydrogen-oxygen mixture explosion, this invention is equipped with a hydrogen vent pipeline 8, an oxygen vent pipeline 9, and a pressure control unit to control the pressure between the hydrogen and oxygen sides in the water electrolysis hydrogen production system, prevent gas leakage, and improve safety.

[0067] Specifically, the pressure control logic of this utility model is as follows:

[0068] When hydrogen emission pipeline 6 and oxygen emission pipeline 7 emit hydrogen and oxygen respectively, there is a certain pressure difference between the two pipelines. This pressure difference is called the initial pressure difference.

[0069] When the pressure P1 in the hydrogen emission pipeline 6 or the pressure P2 in the oxygen emission pipeline 7 changes, the pressure difference ΔP between the two pipelines also changes accordingly.

[0070] The pressure difference ΔP when the pressure P1 in the hydrogen emission pipeline 6 is higher than the pressure P2 in the oxygen emission pipeline 7 is defined as positive, that is, the pressure difference ΔP = P1 - P2 > 0, which is positive;

[0071] The pressure difference ΔP when the pressure in the oxygen discharge pipeline 7 is higher than the pressure in the hydrogen discharge pipeline 6 is set to be negative, that is, the pressure difference ΔP = P1 - P2 < 0, which is negative.

[0072] 1. If the pressure difference ΔP increases, the pressure in the hydrogen discharge pipeline 6 will be significantly higher than the pressure in the oxygen discharge pipeline 7. The controller logic is as follows:

[0073] S1, Electrolytic cell 1 is shut down;

[0074] S2. Close the hydrogen outlet regulating valve 601 and the oxygen outlet regulating valve 701, that is, stop the output of hydrogen and oxygen.

[0075] S3. Open the hydrogen vent valve 801, and hydrogen will be discharged through the hydrogen vent pipeline 8.

[0076] When the pressure difference ΔP decreases to a certain extent, the hydrogen vent valve 801 is closed. Preferably, when the pressure difference ΔP decreases to the initial pressure difference, the electrolytic cell 1 is restarted for operation, and the hydrogen outlet regulating valve 601 and the oxygen outlet regulating valve 701 are opened.

[0077] 2. If the pressure difference ΔP decreases, the pressure in the oxygen discharge line 7 will be significantly higher than the pressure in the hydrogen discharge line 6. The controller logic is as follows:

[0078] S4, Electrolytic cell 1 is shut down;

[0079] S5. Close hydrogen outlet regulating valve 601 and oxygen outlet regulating valve 701;

[0080] S6. Open the oxygen vent valve 901, and oxygen will be discharged from the oxygen vent pipeline 9.

[0081] When the pressure difference ΔP increases to a certain extent, the oxygen vent valve 901 is closed. Preferably, when the pressure difference ΔP increases to the initial pressure difference, the electrolytic cell 1 is restarted for operation, and the hydrogen outlet regulating valve 601 and the oxygen outlet regulating valve 701 are opened.

[0082] Through the pressure control logic described above, the pressure difference between the hydrogen and oxygen sides can be quickly restored in the event of a safety valve tripping or a malfunction of the outlet regulating valve. This minimizes the risk of gas leakage caused by an excessive pressure difference between the hydrogen and oxygen sides. Furthermore, when the pressure difference changes, hydrogen (or oxygen) on the hydrogen side (or oxygen side) can be released in a timely manner to avoid pressure relief through the safety valve tripping, thereby reducing wear and tear on system components.

[0083] The controller mentioned above can be a programmable logic controller (PLC) capable of executing the pressure control logic described above. Other types of processors and their memories can also be used. No specific limitations are made here, and all are within the protection scope of this utility model.

[0084] In some embodiments, the system is further provided with a raw water supply pipeline 11, which is connected to the hydrogen scrubber 4 and the oxygen scrubber 5 respectively, for supplying the raw water required for the scrubbing gas to the hydrogen scrubber 4 and the oxygen scrubber 5 respectively.

[0085] In some embodiments, hydrogen emission line 6 and oxygen emission line 7 are respectively equipped with hydrogen filters and oxygen filters.

[0086] Specifically, the hydrogen filter can be installed on the pipeline between the inlet of the hydrogen emission pipeline 6 and the hydrogen outlet regulating valve 601, or on the pipeline downstream of the hydrogen outlet regulating valve 601. Its function is to filter impurities in the hydrogen.

[0087] An oxygen filter can be installed on the pipeline between the inlet of the oxygen discharge pipeline 7 and the oxygen outlet regulating valve 701, or on the pipeline downstream of the oxygen outlet regulating valve 701. Its function is to filter impurities in the oxygen.

[0088] In some embodiments, flow meters for detecting gas flow are provided on both the hydrogen emission line 6 and the oxygen emission line 7, and the flow meters are electrically connected to the controller.

[0089] In some embodiments, the system further includes an electrolyte recovery tank, which is connected to the first electrolyte outlet and the second electrolyte outlet respectively, for recovering the electrolyte separated in the hydrogen-liquid separator 2 and the oxygen-liquid separator 3.

[0090] More preferably, the electrolyte recovery storage tank is connected to the electrolytic cell 1, so that the collected electrolyte can be passed into the electrolytic cell 1 for reuse.

[0091] In some embodiments, the electrolyzer 1 is an alkaline electrolyzer or a proton exchange membrane electrolyzer (PEM cell). That is, the water electrolysis hydrogen production system provided by the present invention is applicable to both alkaline cells and PEM cells.

[0092] It should be noted that the parameters of the various instruments and valves mentioned above need to be designed according to the actual process system.

[0093] The preferred embodiments of this utility model are provided for guidance. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A water electrolysis hydrogen production system, characterized in that, include: Electrolyzer, hydrogen-side gas-liquid separation unit, oxygen-side gas-liquid separation unit, hydrogen discharge pipeline, oxygen discharge pipeline and pressure control unit; The electrolytic cell is equipped with a cathode hydrogen outlet and an anode oxygen outlet; The hydrogen-side gas-liquid separation unit includes a hydrogen-liquid separator, which has a first inlet and a hydrogen outlet; the first inlet is connected to the cathode hydrogen outlet, and the hydrogen outlet is connected to the inlet of the hydrogen emission pipeline. The oxygen-side gas-liquid separation unit includes an oxygen-liquid separator, which has a second air inlet and an oxygen outlet; the second air inlet is connected to the anode oxygen outlet, and the oxygen outlet is connected to the inlet of the oxygen discharge pipeline. The hydrogen emission pipeline and the oxygen emission pipeline are respectively equipped with a hydrogen outlet regulating valve and an oxygen outlet regulating valve; The pressure control unit includes a hydrogen vent line, an oxygen vent line, a differential pressure gauge, and a controller. The inlet of the hydrogen venting pipeline is located on the pipeline between the hydrogen outlet and the hydrogen outlet regulating valve. The inlet of the oxygen venting pipeline is located on the pipeline between the oxygen outlet and the oxygen outlet regulating valve. The differential pressure gauge is connected to the hydrogen emission pipeline, the oxygen emission pipeline, the hydrogen venting pipeline, and the oxygen venting pipeline, respectively, and is used to detect the pressure difference in the hydrogen emission pipeline, the oxygen emission pipeline, the hydrogen venting pipeline, and the oxygen venting pipeline, respectively. The controller is electrically connected to the differential pressure gauge, the hydrogen outlet regulating valve, and the oxygen outlet regulating valve, respectively.

2. The water electrolysis hydrogen production system according to claim 1, characterized in that, The hydrogen emission pipeline and the oxygen emission pipeline are respectively equipped with hydrogen safety valves and oxygen safety valves. The hydrogen safety valve is installed on the pipeline between the inlet of the hydrogen emission pipeline and the hydrogen outlet regulating valve; The oxygen safety valve is installed on the pipeline between the inlet of the oxygen discharge pipeline and the oxygen outlet regulating valve.

3. The water electrolysis hydrogen production system according to claim 1, characterized in that, The hydrogen venting pipeline is equipped with a hydrogen venting valve, and the oxygen venting pipeline is equipped with an oxygen venting valve. The hydrogen vent valve and the oxygen vent valve are electrically connected to the controller, respectively.

4. The water electrolysis hydrogen production system according to claim 1, characterized in that, The hydrogen-side gas-liquid separation unit also includes a hydrogen scrubber, the inlet of which is connected to the hydrogen outlet, and the outlet of which is connected to the inlet of the hydrogen emission pipeline. The oxygen-side gas-liquid separation unit also includes an oxygen scrubber, the inlet of which is connected to the oxygen outlet, and the outlet of which is connected to the inlet of the oxygen discharge pipeline.

5. The water electrolysis hydrogen production system according to claim 4, characterized in that, The hydrogen-side gas-liquid separation unit also includes a hydrogen condenser, the inlet of which is connected to the outlet of the hydrogen scrubber, and the outlet of which is connected to the inlet of the hydrogen emission pipeline. The oxygen-side gas-liquid separation unit also includes an oxygen condenser, the inlet of which is connected to the outlet of the oxygen scrubber, and the outlet of which is connected to the inlet of the hydrogen emission pipeline.

6. The water electrolysis hydrogen production system according to claim 4, characterized in that, It also includes a raw water supply pipeline, which is connected to the hydrogen scrubber and the oxygen scrubber respectively, for supplying the raw water required for the scrubbing gas to the hydrogen scrubber and the oxygen scrubber respectively.

7. The water electrolysis hydrogen production system according to claim 1, characterized in that, The hydrogen liquid separator is provided with a first liquid outlet, and the oxygen liquid separator is provided with a second liquid outlet. The water electrolysis hydrogen production system further includes a pressure balancing pipeline, the two ends of which are respectively connected to the first liquid outlet and the second liquid outlet, for balancing the pressure in the hydrogen-liquid separator and the oxygen-liquid separator.

8. The water electrolysis hydrogen production system according to claim 1, characterized in that, The hydrogen emission pipeline and the oxygen emission pipeline are respectively equipped with hydrogen filters and oxygen filters.

9. The water electrolysis hydrogen production system according to claim 1, characterized in that, The hydrogen liquid separator is also provided with a first electrolyte outlet, and the oxygen liquid separator is also provided with a second electrolyte outlet. The water electrolysis hydrogen production system further includes an electrolyte recovery storage tank, which is connected to the first electrolyte outlet and the second electrolyte outlet respectively, and is used to recover the electrolyte separated in the hydrogen-liquid separator and the oxygen-liquid separator.

10. The water electrolysis hydrogen production system according to claim 1, characterized in that, The electrolytic cell is an alkaline electrolytic cell or a proton exchange membrane electrolytic cell.

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