PEM electrolytic cell hydrogen production system and control method

Abstract

The invention discloses a PEM electrolytic cell hydrogen production system and a control method, and the system comprises an electrolytic cell which is provided with an oxygen outlet, a first hydrogen outlet and a circulating water inlet; the oxygen branch is provided with an oxygen gas-liquid separator, and the oxygen branch is used for conveying oxygen generated by the electrolytic cell; the hydrogen branch is provided with a hydrogen gas-liquid separator, and the hydrogen branch is used for conveying hydrogen generated by the electrolytic cell; the circulating water loop is used for conveying water separated by the oxygen gas-liquid separator to the electrolytic bath; and the detection gas branch is used for introducing the preset detection gas into the electrolytic bath through the oxygen branch or introducing the preset detection gas into the electrolytic bath through the oxygen branch and the hydrogen branch, and the preset detection gas is introduced into the electrolytic bath through the detection gas branch, so that on the premise that the electrolytic bath is not disassembled, the preset detection gas is introduced into the electrolytic bath through the oxygen branch and the hydrogen branch. Inner leakage and outer leakage detection can be accurately carried out on the electrolytic cell, and the operation reliability of the PEM electrolytic cell hydrogen production system is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electrolytic hydrogen production, and in particular to a PEM electrolyzer hydrogen production system and control method. Background Art

[0002] As the hydrogen energy industry is developing rapidly, PEM (Proton Exchange Membrane) electrolyzer hydrogen production technology is increasingly gaining attention in the hydrogen production industry due to its advantages of small equipment size, high current density, fast dynamic response, and efficient coupling with wind power and photovoltaics.

[0003] The core material of the PEM electrolyzer is the membrane electrode, which not only serves as the center of the hydrogen and oxygen evolution reactions, but also serves to isolate the hydrogen and oxygen in the electrolyzer. The membrane electrode has relatively high requirements for equipment assembly and operating conditions. During the operation of the PEM electrolyzer, the following phenomena may occur: 1) The local temperature in the sealing area of ​​the electrolyzer is too high or the pressure is too high, causing some gaskets to fail; 2) The local high temperature in the active area of ​​the electrolyzer or the titanium felt has wire ends, causing the membrane electrode to be perforated, resulting in internal and external leakage in the electrolyzer, which brings hidden dangers to the safe operation of the electrolyzer.

[0004] For the PEM electrolyzer hydrogen production systems that have been delivered and put into operation, there is currently no effective means to promptly confirm the leakage of the electrolyzer, resulting in reduced system operation reliability.

[0005] Therefore, how to provide a PEM electrolyzer hydrogen production system with higher reliability is a technical problem that needs to be solved. Summary of the invention

[0006] The embodiments of the present application provide a PEM electrolyzer hydrogen production system and a control method to improve the operational reliability of the PEM electrolyzer hydrogen production system.

[0007] In a first aspect, a PEM electrolyzer hydrogen production system is provided, the system comprising: an electrolyzer, provided with an oxygen outlet, a first hydrogen outlet and a circulating water inlet; an oxygen branch, provided with an oxygen gas-liquid separator, the oxygen branch is used to transport the oxygen generated by the electrolyzer; a hydrogen branch, provided with a hydrogen gas-liquid separator, the hydrogen branch is used to transport the hydrogen generated by the electrolyzer; a circulating water loop, used to transport the water separated by the oxygen gas-liquid separator to the electrolyzer; a detection gas branch, used to pass a preset detection gas into the electrolyzer through the oxygen branch, or to pass the preset detection gas into the electrolyzer through the oxygen branch and the hydrogen branch; wherein the inlet of the oxygen branch is connected to the oxygen outlet, the inlet of the hydrogen branch is connected to the first hydrogen outlet, the inlet of the circulating water loop is connected to the bottom outlet of the oxygen gas-liquid separator, the outlet of the circulating water loop is connected to the circulating water inlet, and the detection gas branch is connected to the bottom outlet of the oxygen gas-liquid separator and the bottom outlet of the hydrogen gas-liquid separator.

[0008] In some embodiments, the electrolyzer is further provided with a second hydrogen outlet, and the system further includes: a first emptying branch, used to discharge the preset detection gas entering the electrolyzer at a first preset flow rate, the first emptying branch being connected to the circulating water inlet; a second emptying branch, used to discharge the hydrogen entering the electrolyzer at a second preset flow rate, the second emptying branch being connected to the second hydrogen outlet and the hydrogen branch; an electrode detection device, connected to the bipolar plates of each chamber in the electrolyzer, for performing preset detection on the membrane electrode of each chamber.

[0009] In some embodiments, the first emptying branch includes a first three-way valve, a first flow regulating valve and a first flow meter, and the second emptying branch includes a second three-way valve, a second flow regulating valve and a second flow meter, wherein the first interface and the second interface of the first three-way valve are connected in series to the circulating water circuit, the third interface of the first three-way valve is emptied after passing through the first flow regulating valve and the first flow meter, the first interface of the second three-way valve is connected to the second hydrogen outlet, the second interface of the second three-way valve is connected to the hydrogen branch, and the third interface of the second three-way valve is emptied after passing through the second flow regulating valve and the second flow meter.

[0010] In some embodiments, the oxygen branch further includes a first pressure regulating valve and a second pressure regulating valve, the hydrogen branch further includes a third pressure regulating valve and a fourth pressure regulating valve, and the detection gas branch includes a fifth pressure regulating valve and a third flow regulating valve, wherein the first pressure regulating valve and the second pressure regulating valve are respectively arranged at the inlet and outlet of the oxygen branch, the third pressure regulating valve and the fourth pressure regulating valve are respectively arranged at the inlet and outlet of the hydrogen branch, the outlet of the fifth pressure regulating valve and the inlet of the third flow regulating valve are connected to the bottom outlet of the oxygen gas-liquid separator, the outlet of the third flow regulating valve is connected to the bottom outlet of the hydrogen gas-liquid separator, and the inlet of the fifth pressure regulating valve is the input port of the preset detection gas.

[0011] In some embodiments, the system further includes: a heat exchanger, comprising a first pipe pass for conveying oxygen and a second pipe pass for conveying circulating water; wherein the first pipe pass is arranged between the outlet of the first pressure regulating valve and the inlet of the oxygen gas-liquid separator, and the second pipe pass is connected in series to the circulating water loop.

[0012] In some embodiments, the circulating water loop is provided with a circulating pump and a metal ion filter, the inlet of the second pipe side is the inlet of the circulating water loop, the outlet of the second pipe side is connected to the inlet of the circulating pump, the outlet of the circulating pump is connected to the inlet of the metal ion filter, and the outlet of the metal ion filter is the outlet of the circulating water loop.

[0013] In some embodiments, the system further includes: a temperature sensor for detecting the temperature of water in the oxygen gas-liquid separator; and a temperature control unit for obtaining the temperature from the temperature sensor and making the temperature within a preset temperature range.

[0014] In a second aspect, a control method for a PEM electrolyzer hydrogen production system is provided, which is applied to the PEM electrolyzer hydrogen production system as described in the first aspect, and the method includes: obtaining a detection instruction; if the detection instruction is an internal leakage detection instruction, causing the system to stop hydrogen production and discharge the hydrogen and oxygen in the electrolyzer, the oxygen branch and the hydrogen branch, and then passing the preset detection gas into the oxygen gas-liquid separator based on the detection gas branch; adjusting the first gas pressure in the oxygen branch, and when the first gas pressure reaches a first preset pressure, passing the preset detection gas into the electrolyzer based on the oxygen branch, and maintaining the pressure in the electrolyzer; determining the internal leakage detection result according to the pressure of the oxygen outlet, the pressure of the circulating water inlet and the pressure of the first hydrogen outlet.

[0015] In some embodiments, after obtaining the detection instruction, the method further includes: if the detection instruction is a leakage detection instruction, causing the system to stop producing hydrogen, and discharge the hydrogen and oxygen in the electrolyzer, the oxygen branch, and the hydrogen branch, and then based on the detection gas branch, respectively passing the preset detection gas into the oxygen gas-liquid separator and the hydrogen gas-liquid separator; adjusting the first air pressure, and when the first air pressure reaches the first preset pressure, passing the preset detection gas into the electrolyzer based on the oxygen branch, and maintaining the pressure in the electrolyzer; adjusting the second air pressure in the hydrogen branch, and when the second air pressure reaches the first preset pressure, passing the preset detection gas into the electrolyzer based on the hydrogen branch, and maintaining the pressure in the electrolyzer; determining the leakage detection result according to the pressure of the oxygen outlet, the pressure of the first hydrogen outlet, and the pressure of the circulating water inlet.

[0016] In some embodiments, after obtaining the detection instruction, the method further includes: if the detection instruction is an electrode detection instruction, starting the system to produce hydrogen, and stopping hydrogen production after maintaining a preset time, and discharging oxygen in the oxygen branch, and then passing the preset detection gas into the oxygen gas-liquid separator based on the detection gas branch; adjusting the first gas pressure so that the first gas pressure first reaches the first preset pressure, and then decreases to a second preset pressure, and passing the preset detection gas into the electrolyzer based on the oxygen branch; adjusting the second gas pressure so that the second gas pressure first reaches the first preset pressure, and then decreases to the second preset pressure, and reversely passing hydrogen into the electrolyzer based on the hydrogen branch; emptying the preset detection gas at the circulating water inlet at a first preset flow rate, and emptying the hydrogen at a second preset flow rate at the second hydrogen outlet on the electrolyzer; starting the electrode detection device, and determining the electrode detection result according to the output result of the electrode detection device, wherein the electrode detection device is connected to the bipolar plates of each chamber in the electrolyzer.

[0017] By applying the above technical scheme, a PEM electrolyzer hydrogen production system includes: an electrolyzer, provided with an oxygen outlet, a first hydrogen outlet and a circulating water inlet; an oxygen branch, provided with an oxygen gas-liquid separator, the oxygen branch is used to transport the oxygen generated by the electrolyzer; a hydrogen branch, provided with a hydrogen gas-liquid separator, the hydrogen branch is used to transport the hydrogen generated by the electrolyzer; a circulating water loop, used to transport the water separated by the oxygen gas-liquid separator to the electrolyzer; a detection gas branch, used to pass a preset detection gas into the electrolyzer through the oxygen branch, or to pass a preset detection gas into the electrolyzer through the oxygen branch and the hydrogen branch. By setting the detection gas branch and passing the preset detection gas into the electrolyzer, it is possible to accurately detect internal and external leakage of the electrolyzer without disassembling the electrolyzer, thereby improving the operating reliability of the PEM electrolyzer hydrogen production system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a PEM electrolyzer hydrogen production system proposed in an embodiment of the present application;

[0019] Figure 2 A schematic flow chart of a control method for a PEM electrolyzer hydrogen production system proposed in an embodiment of the present application;

[0020] Figure 3 A schematic flow chart of a control method for a PEM electrolyzer hydrogen production system proposed in another embodiment of the present application;

[0021] Figure 4 A schematic flow chart of a control method for a PEM electrolyzer hydrogen production system proposed in yet another embodiment of the present application.

[0022] Figure 1 Among them, 1. electrolytic cell; 2. heat exchanger; 3. oxygen gas-liquid separator; 4. hydrogen gas-liquid separator; 5. circulation pump; 6. metal ion filter; 7. electrode detection device; 8. temperature control unit; 9. second pressure regulating valve; 10. fourth pressure regulating valve; 11. temperature sensor; 12. fifth pressure regulating valve; 13. third flow regulating valve; 14. first pressure regulating valve; 15. third pressure regulating valve; 16. second three-way valve; 17. first three-way valve; 18. second flow regulating valve; 19. first flow regulating valve; 20. second flow meter; 21. first flow meter; 22. third pressure gauge; 23. second pressure gauge; 24. first pressure gauge; 25. fourth pressure gauge. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] It should be noted that those skilled in the art will easily think of other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present application are indicated by the claims.

[0025] It should be understood that the present application is not limited to the precise structures described below and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

[0026] An embodiment of the present application provides a PEM electrolyzer hydrogen production system, in which a preset detection gas can enter the electrolyzer through an internal leakage detection flow path and an external leakage detection flow path respectively, thereby realizing the detection of internal leakage and external leakage of the electrolyzer without disassembling the electrolyzer, thereby improving the operating reliability of the PEM electrolyzer hydrogen production system.

[0027] like Figure 1 As shown, the system includes:

[0028] The electrolytic cell 1 is provided with an oxygen outlet, a first hydrogen outlet and a circulating water inlet;

[0029] An oxygen branch is provided with an oxygen gas-liquid separator 3, and the oxygen branch is used to transport the oxygen generated by the electrolyzer 1;

[0030] A hydrogen branch is provided with a hydrogen gas-liquid separator 4, and the hydrogen branch is used to transport the hydrogen generated by the electrolyzer 1;

[0031] A circulating water loop for conveying the water separated by the oxygen gas-liquid separator 3 to the electrolyzer 1;

[0032] A detection gas branch, used to pass a preset detection gas into the electrolyzer 1 through the oxygen branch, or to pass a preset detection gas into the electrolyzer 1 through the oxygen branch and the hydrogen branch;

[0033] Among them, the inlet of the oxygen branch is connected to the oxygen outlet, the inlet of the hydrogen branch is connected to the first hydrogen outlet, the inlet of the circulating water loop is connected to the bottom outlet of the oxygen gas-liquid separator 3, the outlet of the circulating water loop is connected to the circulating water inlet, and the detection gas branch is connected to the bottom outlet of the oxygen gas-liquid separator 3 and the bottom outlet of the hydrogen gas-liquid separator 4.

[0034] In this embodiment, the PEM electrolyzer hydrogen production system includes an electrolyzer 1, an oxygen branch, a hydrogen branch, a circulating water loop and a detection gas branch. An electrolysis reaction is carried out in the electrolyzer 1, and the generated oxygen and hydrogen are output to subsequent work sections through the oxygen branch and the hydrogen branch respectively. The water separated in the oxygen gas-liquid separator 3 returns to the electrolyzer 1 through the circulating water loop to continue the electrolysis reaction. When it is necessary to detect internal or external leakage of the electrolyzer 1, the system hydrogen production is stopped, and the detection gas in the detection gas branch is passed into the electrolyzer 1, and internal or external leakage detection can be carried out, wherein internal leakage refers to leakage between the hydrogen side and the oxygen side in the electrolyzer 1, and external leakage refers to leakage of the hydrogen side and / or the oxygen side to the outside of the electrolyzer 1.

[0035] Specifically, when conducting internal leakage detection, the system stops hydrogen production and discharges hydrogen and oxygen in the electrolyzer 1, oxygen branch and hydrogen branch, and then the preset detection gas is introduced into the electrolyzer 1 through the oxygen branch. The internal leakage detection result can be determined by detecting the pressure of the first hydrogen outlet, the pressure of the oxygen outlet and the pressure of the circulating water inlet of the electrolyzer 1. If the pressure of the oxygen outlet and the pressure of the circulating water inlet are fixed pressures, and the pressure of the first hydrogen outlet is zero, it means that there is no internal leakage. If the pressure of the oxygen outlet and the pressure of the circulating water inlet decrease, and the pressure of the first hydrogen outlet is not zero, it means that there is an internal leakage. The decrease in the pressure of the oxygen outlet and the pressure of the circulating water inlet should be consistent or close, otherwise, the pressure gauge or pressure measuring point of the oxygen outlet or the circulating water inlet needs to be calibrated.

[0036] When conducting leakage detection, the system stops producing hydrogen and discharges hydrogen and oxygen in the electrolyzer 1, the oxygen branch and the hydrogen branch. Then, a preset detection gas is introduced into the electrolyzer 1 through the oxygen branch and the hydrogen branch. The leakage detection result is determined by detecting the pressure of the oxygen outlet of the electrolyzer 1, the pressure of the first hydrogen outlet and the pressure of the circulating water inlet. Specifically, if any one of the pressure of the oxygen outlet, the pressure of the first hydrogen outlet and the pressure of the circulating water inlet decreases, it indicates that there is leakage.

[0037] It can be understood that stopping the system from producing hydrogen includes stopping the electrolysis reaction in the electrolyzer 1 and stopping the water in the circulating water loop from entering the electrolyzer 1 .

[0038] Optionally, the preset detection gas is any one of gases including air, nitrogen, inert gas, etc.

[0039] By setting up a detection gas branch, a preset detection gas is introduced into the electrolyzer 1 through the oxygen branch, or through the oxygen branch and the hydrogen branch, so that the internal leakage and external leakage detection of the electrolyzer 1 can be accurately performed without disassembling the electrolyzer 1, so that when the leakage is found, it can be handled in time, thereby improving the operating reliability of the PEM electrolyzer hydrogen production system.

[0040] In some embodiments of the present application, the electrolyzer 1 is further provided with a second hydrogen outlet, and the system further comprises:

[0041] A first emptying branch, used to discharge the preset detection gas entering the electrolytic cell 1 at a first preset flow rate, the first emptying branch being connected to a circulating water inlet;

[0042] A second exhaust branch, used to discharge the hydrogen entering the electrolyzer 1 at a second preset flow rate, the second exhaust branch connecting the second hydrogen outlet and the hydrogen branch;

[0043] The electrode detection device 7 is connected to the bipolar plates of each chamber in the electrolytic cell 1 and is used to perform preset detection on the membrane electrode of each chamber.

[0044] In this embodiment, the electrolyzer 1 is also provided with a second hydrogen outlet, and the system further includes a first emptying branch, a second emptying branch and an electrode detection device 7, wherein the electrode detection device 7 is connected to the bipolar plates of each chamber in the electrolyzer 1. When performing electrode detection, the system is started to produce hydrogen, and hydrogen production is stopped after maintaining a preset time, and the oxygen in the oxygen branch is discharged, and then a certain amount of hydrogen is stored in the hydrogen gas-liquid separator 4 and the pressure reaches a preset value, and then the preset detection gas in the detection gas branch is introduced into the preset detection gas through the oxygen branch side, and the preset detection gas in the electrolyzer 1 is emptied through the first emptying branch, and the hydrogen in the hydrogen gas-liquid separator 4 is reversely introduced into the electrolyzer 1, and the hydrogen in the electrolyzer 1 is emptied through the second emptying branch, and then the electrode detection device 7 is started. If there is a defect in the electrode (such as perforation, etc.), the hydrogen introduced into the electrolyzer 1 will oxidize the electrode, and the electrode detection device 7 can detect the change of the detection parameters (such as current, voltage) caused by oxidation, thereby determining whether the electrode has a defect.

[0045] It is understandable that when performing internal leakage and external leakage detection, the first emptying branch and the second emptying branch are kept in a closed state.

[0046] Optionally, the type of the electrode detection device 7 is determined by a preset detection item, and the preset detection item may include one or more of a hydrogen permeation curve, an AC impedance curve, a cyclic voltammetry curve, and a polarization curve. For example, if the preset detection item is a hydrogen permeation curve, the electrode detection device 7 may be an electrochemical constant potential scanner, and if there are multiple preset detection items, the electrode detection device 7 may be an electrode detection workstation.

[0047] Optionally, the first preset flow rate may be the same as the second preset flow rate, or may be different from the second preset flow rate.

[0048] By providing the first emptying branch, the second emptying branch and the electrode detection device 7, the membrane electrode detection of each chamber of the electrolytic cell 1 is realized, so that the leakage of the membrane electrode is accurately determined, thereby further improving the reliability of the system.

[0049] Optionally, when the system is producing hydrogen normally, the second exhaust branch can be closed, and the hydrogen in the electrolyzer 1 is introduced into the hydrogen branch through at least one of the first hydrogen outlet and the second hydrogen outlet.

[0050] In some embodiments of the present application, the first emptying branch includes a first three-way valve 17, a first flow regulating valve 19 and a first flow meter 21, and the second emptying branch includes a second three-way valve 16, a second flow regulating valve 18 and a second flow meter 20, wherein the first interface and the second interface of the first three-way valve 17 are connected in series in a circulating water loop, the third interface of the first three-way valve 17 is emptied after passing through the first flow regulating valve 19 and the first flow meter 21, the first interface of the second three-way valve 16 is connected to the second hydrogen outlet, the second interface of the second three-way valve 16 is connected to the hydrogen branch, and the third interface of the second three-way valve 16 is emptied after passing through the second flow regulating valve 18 and the second flow meter 20.

[0051] In this embodiment, the discharge flow rate of the preset detection gas is adjusted by the first flow regulating valve 19, and the discharge flow rate of hydrogen is adjusted by the second flow regulating valve 18, thereby achieving more accurate flow control and improving the accuracy of electrode detection.

[0052] Figure 1 In the figure, the first flow meter 21 is arranged after the first flow regulating valve 19, and the second flow meter 20 is arranged after the second flow regulating valve 18. Optionally, the first flow meter 21 can also be arranged between the first three-way valve 17 and the first flow regulating valve 19, and the second flow meter 20 can also be arranged between the second three-way valve 16 and the second flow regulating valve 18.

[0053] In some embodiments of the present application, the oxygen branch also includes a first pressure regulating valve 14 and a second pressure regulating valve 9, the hydrogen branch also includes a third pressure regulating valve 15 and a fourth pressure regulating valve 10, and the detection gas branch includes a fifth pressure regulating valve 12 and a third flow regulating valve 13, wherein the first pressure regulating valve 14 and the second pressure regulating valve 9 are respectively arranged at the inlet and outlet of the oxygen branch, the third pressure regulating valve 15 and the fourth pressure regulating valve 10 are respectively arranged at the inlet and outlet of the hydrogen branch, the outlet of the fifth pressure regulating valve 12 and the inlet of the third flow regulating valve 13 are connected to the bottom outlet of the oxygen gas-liquid separator 3, the outlet of the third flow regulating valve 13 is connected to the bottom outlet of the hydrogen gas-liquid separator 4, and the inlet of the fifth pressure regulating valve 12 is the input port of the preset detection gas.

[0054] Specifically, when the system is producing hydrogen normally, the oxygen generated by the electrolyzer 1 enters the oxygen gas-liquid separator 3 through the first pressure regulating valve 14 for gas-liquid separation, and the separated oxygen is sent to the subsequent process section through the second pressure regulating valve 9. The hydrogen generated by the electrolyzer 1 enters the hydrogen gas-liquid separator 4 through the third pressure regulating valve 15, and the separated hydrogen enters the subsequent process section through the fourth pressure regulating valve 10. At the same time, the water separated in the oxygen gas-liquid separator 3 is transported to the electrolyzer 1 through the circulating water loop to continue the electrolysis reaction.

[0055] When internal leakage detection is required, the system stops hydrogen production, and the hydrogen and oxygen in the electrolyzer 1, the oxygen branch and the hydrogen branch are discharged. Then, the fifth pressure regulating valve 12 is opened to allow the preset detection gas to enter from the bottom outlet of the oxygen gas-liquid separator 3, and the second pressure regulating valve 9 is adjusted to allow the first gas pressure in the oxygen branch to reach the first preset pressure. After the preset detection gas is moistened in the oxygen gas-liquid separator 3, it is discharged from the inlet of the oxygen gas-liquid separator 3, enters the electrolyzer 1 from the oxygen outlet through the first pressure regulating valve 14, and is pressure-maintained in the electrolyzer 1. By detecting the pressure of the first hydrogen outlet, the pressure of the oxygen outlet and the pressure of the circulating water inlet of the electrolyzer 1, the internal leakage detection result can be determined. If the pressure of the oxygen outlet and the pressure of the circulating water inlet are fixed pressures, and the pressure of the first hydrogen outlet is zero, it indicates that there is no internal leakage. If the pressure of the oxygen outlet and the pressure of the circulating water inlet decrease, and the pressure of the first hydrogen outlet is not zero, it indicates that there is an internal leakage.

[0056] When leakage detection is required, the system stops producing hydrogen, and the hydrogen and oxygen in the electrolyzer 1, the oxygen branch and the hydrogen branch are discharged, and then the preset detection gas is introduced into the oxygen side and the hydrogen side of the electrolyzer 1 at the same time, wherein, for the oxygen side, the fifth pressure regulating valve 12 is opened to allow the preset detection gas to enter from the bottom outlet of the oxygen gas-liquid separator 3, and the second pressure regulating valve 9 is adjusted to make the first pressure in the oxygen branch reach the first preset pressure, and the preset detection gas is moistened in the oxygen gas-liquid separator 3, and then discharged from the inlet of the oxygen gas-liquid separator 3, and enters the electrolyzer 1 from the oxygen outlet through the first pressure regulating valve 14, and is maintained under pressure in the electrolyzer 1. For the hydrogen side, the third flow regulating valve 13 is opened to allow the preset detection gas to enter from the bottom outlet of the hydrogen gas-liquid separator 4, and the fourth pressure regulating valve 10 is adjusted to allow the second pressure in the hydrogen branch to reach the first preset pressure. The preset detection gas is moistened in the hydrogen gas-liquid separator 4, then discharged from the inlet of the hydrogen gas-liquid separator 4, and enters the electrolyzer 1 from the first hydrogen outlet through the third pressure regulating valve 15, and is pressure-maintained in the electrolyzer 1. The leakage detection result is determined by detecting the pressure of the oxygen outlet of the electrolyzer 1, the pressure of the first hydrogen outlet, and the pressure of the circulating water inlet. Specifically, if any of the pressure of the oxygen outlet, the pressure of the first hydrogen outlet, and the pressure of the circulating water inlet drops, it indicates that there is leakage.

[0057] When performing electrode detection, the system is started to produce hydrogen, and after maintaining the preset time, the hydrogen production is stopped, and the oxygen in the oxygen branch is discharged, and then a certain amount of hydrogen is stored in the hydrogen gas-liquid separator 4 and the pressure reaches a preset value, and then the fifth pressure regulating valve 12 is opened and the second pressure regulating valve 9 is adjusted to make the first air pressure in the oxygen branch reach the first preset pressure, and the first pressure regulating valve 14 is adjusted to stably reduce the first air pressure to the second preset pressure, and the preset detection gas is introduced into the electrolyzer 1 from the oxygen outlet, and at the same time, the fourth pressure regulating valve 10 is adjusted to make the second air pressure in the hydrogen branch reach The first preset pressure is adjusted, and the third pressure regulating valve 15 is adjusted to stably reduce the second gas pressure to the second preset pressure, and the hydrogen is reversely introduced into the electrolytic cell 1 from the first hydrogen outlet, and the preset detection gas is emptied at a first preset flow rate through the first emptying branch, and the hydrogen is emptied at a second preset flow rate through the second emptying branch. Finally, the electrode detection device 7 is started. If there is a defect in the electrode (such as perforation, etc.), the hydrogen introduced into the electrolytic cell 1 will oxidize the electrode. The electrode detection device 7 can detect the changes in the detection parameters (such as current and voltage) caused by oxidation, thereby determining whether there is a defect in the electrode.

[0058] It is understandable that, since it is not necessary to introduce nitrogen into the hydrogen side when the electrode detection is performed, the third flow regulating valve 13 remains closed when the electrode detection is performed.

[0059] In some embodiments of the present application, in order to recover the water separated by the hydrogen gas-liquid separator, when the system is producing hydrogen normally, if the water level in the hydrogen gas-liquid separator 4 is higher than the preset water level, the third flow regulating valve 13 is opened to pass the water in the hydrogen gas-liquid separator into the circulating water loop for recovery.

[0060] It should be noted that those skilled in the art may, as needed, set other pressure regulating valves, or manual valves, or pressure and temperature measuring points, as well as other components that can be set in the pipelines in the oxygen branch, hydrogen branch and detection gas branch, which does not affect the scope of protection of the present application.

[0061] In some embodiments of the present application, the system further includes:

[0062] Heat exchanger 2, comprising a first tube pass for conveying oxygen and a second tube pass for conveying circulating water;

[0063] The first pipe pass is arranged between the outlet of the first pressure regulating valve 14 and the inlet of the oxygen gas-liquid separator 3, and the second pipe pass is connected in series to the circulating water loop.

[0064] In this embodiment, by providing a heat exchanger 2, the oxygen entering the first tube pass can exchange heat with the circulating water entering the second tube pass, thereby increasing the temperature of the circulating water and further improving the electrolysis efficiency.

[0065] In some embodiments of the present application, the circulating water loop is provided with a circulating pump 5 and a metal ion filter 6, the inlet of the second pipe pass is the inlet of the circulating water loop, the outlet of the second pipe pass is connected to the inlet of the circulating pump 5, the outlet of the circulating pump 5 is connected to the inlet of the metal ion filter 6, and the outlet of the metal ion filter 6 is the outlet of the circulating water loop.

[0066] In this embodiment, a circulation pump 5 is provided in the circulating water loop to improve the circulation efficiency, and impurities in the circulating water are removed by the metal ion filter 6 to improve the water quality of the circulating water.

[0067] Optionally, when the circulating water loop is provided with a circulating pump 5 and a metal ion filter 6 , the first three-way valve 17 may be provided between the circulating pump 5 and the metal ion filter 6 , or between the metal ion filter 6 and the circulating water inlet of the electrolytic cell 1 .

[0068] Optionally, if the heat exchanger 2 is not provided in the system, the inlet of the circulation pump 5 is the inlet of the circulating water loop.

[0069] In some embodiments of the present application, the system further includes:

[0070] The temperature sensor 11 is used to detect the temperature of water in the oxygen gas-liquid separator 3;

[0071] The temperature control unit 8 is used to obtain the temperature from the temperature sensor 11 and keep the temperature within a preset temperature range.

[0072] In this embodiment, the temperature of the water in the oxygen gas-liquid separator 3 is detected by the temperature sensor 11. If the temperature control unit 8 detects that the temperature is not within the preset temperature range, the temperature control unit 8 controls the temperature of the water in the oxygen gas-liquid separator 3 so that the water temperature is within the preset temperature range.

[0073] Optionally, the oxygen gas-liquid separator 3 is provided with a cooling water coil, and the temperature control unit 8 controls the temperature of the water in the oxygen gas-liquid separator 3 by controlling the temperature of the medium in the cooling water coil.

[0074] Optionally, the preset temperature range may be one, or multiple preset temperature ranges may be set according to different system operating conditions. For example, when the system is producing hydrogen normally, the preset temperature range is the first temperature range. When performing internal or external leakage detection, the preset temperature range is the second temperature range.

[0075] By providing the temperature sensor 11 and the temperature control unit 8, the temperature of the circulating water can be controlled according to different system operating conditions, thereby improving the operating reliability of the system.

[0076] In some embodiments of the present application, the oxygen outlet, the first hydrogen outlet, the second hydrogen outlet and the circulating water inlet are respectively provided with a first pressure gauge 24, a second pressure gauge 23, a third pressure gauge 22 and a fourth pressure gauge 25.

[0077] In this embodiment, by providing the first pressure gauge 24, the second pressure gauge 23, the third pressure gauge 22 and the fourth pressure gauge 25, accurate pressure detection can be performed, so that internal leakage, external leakage detection and electrode detection of the system can be performed more accurately.

[0078] Optionally, the first pressure gauge 24, the second pressure gauge 23, the third pressure gauge 22 and the fourth pressure gauge 25 may be replaced with pressure sensors, and each pressure value may be acquired through the pressure sensors.

[0079] The PEM electrolyzer hydrogen production system in the embodiment of the present application includes: an electrolyzer, which is provided with an oxygen outlet, a first hydrogen outlet and a circulating water inlet; an oxygen branch, which is provided with an oxygen gas-liquid separator, and the oxygen branch is used to transport the oxygen generated by the electrolyzer; a hydrogen branch, which is provided with a hydrogen gas-liquid separator, and the hydrogen branch is used to transport the hydrogen generated by the electrolyzer; a circulating water loop, which is used to transport the water separated by the oxygen gas-liquid separator to the electrolyzer; a detection gas branch, which is used to pass a preset detection gas into the electrolyzer through the oxygen branch, or to pass a preset detection gas into the electrolyzer through the oxygen branch and the hydrogen branch. By setting the detection gas branch and passing the preset detection gas into the electrolyzer, it is achieved that the internal and external leakage detection of the electrolyzer is accurately performed without disassembling the electrolyzer, so that when a leak is found, it can be handled in time, thereby improving the operating reliability of the PEM electrolyzer hydrogen production system.

[0080] The present application also provides a control method for a PEM electrolyzer hydrogen production system, which is applied to the above PEM electrolyzer hydrogen production system. Figure 2 As shown, the method comprises the following steps:

[0081] Step S101, obtaining a detection instruction.

[0082] The detection instruction includes any one of an internal leakage detection instruction, an external leakage detection instruction and an electrode detection instruction. The detection instruction can be input by a user or automatically triggered when a preset condition is met, and the preset condition can be, for example, reaching a preset hydrogen production operation time.

[0083] Step S102, if the detection instruction is an internal leakage detection instruction, the system stops producing hydrogen, and discharges the hydrogen and oxygen in the electrolyzer, the oxygen branch and the hydrogen branch, and then passes the preset detection gas into the oxygen gas-liquid separator based on the detection gas branch.

[0084] Step S103, adjusting the first air pressure in the oxygen branch, and when the first air pressure reaches a first preset pressure, passing the preset detection gas into the electrolytic cell based on the oxygen branch, and maintaining the pressure in the electrolytic cell.

[0085] Step S104, determining an internal leakage detection result according to the pressure of the oxygen outlet, the pressure of the circulating water inlet and the pressure of the first hydrogen outlet.

[0086] Specifically, if the pressure at the oxygen outlet and the pressure at the circulating water inlet are fixed pressures, and the pressure at the first hydrogen outlet is zero, it indicates that there is no internal leakage; if the pressure at the oxygen outlet and the pressure at the circulating water inlet decrease, and the pressure at the first hydrogen outlet is not zero, it indicates that there is an internal leakage.

[0087] By passing the preset detection gas into the electrolyzer through the oxygen branch for pressure detection, it is possible to accurately detect internal leakage of the electrolyzer without disassembling the electrolyzer, so that when internal leakage is found, it can be dealt with in time, thereby improving the operating reliability of the PEM electrolyzer hydrogen production system.

[0088] The present application also provides a control method for a PEM electrolyzer hydrogen production system, which is applied to the above PEM electrolyzer hydrogen production system. Figure 3 As shown, the method comprises the following steps:

[0089] Step S201, obtaining a detection instruction.

[0090] Step S202, if the detection instruction is a leakage detection instruction, the system stops producing hydrogen and discharges the hydrogen and oxygen in the electrolyzer, the oxygen branch and the hydrogen branch, and then based on the detection gas branch, the preset detection gas is respectively introduced into the oxygen gas-liquid separator and the hydrogen gas-liquid separator.

[0091] Step S203, adjusting the first gas pressure, when the first gas pressure reaches the first preset pressure, passing the preset detection gas into the electrolytic cell based on the oxygen branch, and maintaining the pressure in the electrolytic cell.

[0092] Step S204, adjusting the second gas pressure in the hydrogen branch, when the second gas pressure reaches the first preset pressure, passing the preset detection gas into the electrolytic cell based on the hydrogen branch, and maintaining the pressure in the electrolytic cell.

[0093] Step S205, determining a leakage detection result according to the pressure of the oxygen outlet, the pressure of the first hydrogen outlet, and the pressure of the circulating water inlet.

[0094] Specifically, if any one of the pressure at the oxygen outlet, the pressure at the first hydrogen outlet, and the pressure at the circulating water inlet decreases, it indicates that there is leakage.

[0095] In this embodiment, by passing a preset detection gas into the hydrogen side and oxygen side of the electrolyzer, accurate leakage detection of the electrolyzer is achieved without disassembling the electrolyzer, so that timely processing can be carried out when leakage is found, thereby improving the operating reliability of the PEM electrolyzer hydrogen production system.

[0096] The present application also provides a control method for a PEM electrolyzer hydrogen production system, which is applied to the above PEM electrolyzer hydrogen production system. Figure 4 As shown, the method comprises the following steps:

[0097] Step S301, obtaining a detection instruction.

[0098] Step S302, if the detection instruction is an electrode detection instruction, start the system to produce hydrogen, and stop hydrogen production after maintaining a preset time, and discharge the oxygen in the oxygen branch, and then pass the preset detection gas into the oxygen gas-liquid separator based on the detection gas branch.

[0099] Step S303, adjusting the first gas pressure so that the first gas pressure first reaches the first preset pressure and then decreases to a second preset pressure, and passing the preset detection gas into the electrolytic cell based on the oxygen branch.

[0100] Step S304, adjusting the second gas pressure so that the second gas pressure first reaches the first preset pressure and then decreases to the second preset pressure, and reversely introducing hydrogen into the electrolytic cell based on the hydrogen branch.

[0101] It is understandable that the second preset pressure is less than the first preset pressure. By making the first air pressure and the second air pressure reach the first preset pressure first and then decrease to the second preset pressure, the stability during pressure regulation is improved.

[0102] Step S305, the preset detection gas is discharged at the circulating water inlet at a first preset flow rate, and the hydrogen is discharged at the second hydrogen outlet on the electrolyzer at a second preset flow rate.

[0103] Optionally, the first preset flow rate may be the same as the second preset flow rate, or may be different from the second preset flow rate.

[0104] Step S306, starting the electrode detection device, and determining the electrode detection result according to the output result of the electrode detection device, wherein the electrode detection device is connected to the bipolar plates of each chamber in the electrolytic cell.

[0105] In this embodiment, a preset detection gas is introduced into the oxygen side of the electrolyzer and is exhausted at the circulating water inlet, hydrogen is introduced into the hydrogen side of the electrolyzer and the hydrogen in the electrolyzer is exhausted at the second hydrogen outlet, and then the electrode detection device is started to detect the bipolar plates of each chamber to accurately determine whether the electrode has defects, so that when electrode defects are found, they can be dealt with in a timely manner, thereby improving the operating reliability of the PEM electrolyzer hydrogen production system.

[0106] For other embodiments of the control method of a PEM electrolyzer hydrogen production system of the present application, reference may be made to the relevant embodiments of a PEM electrolyzer hydrogen production system of the present application.

[0107] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0108] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0109] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A PEM electrolyzer hydrogen production system, It is characterized in that The system comprises: The electrolyzer is provided with an oxygen outlet, a first hydrogen outlet and a circulating water inlet; An oxygen branch is provided with an oxygen gas-liquid separator, and the oxygen branch is used to transport the oxygen generated by the electrolyzer; A hydrogen branch is provided with a hydrogen gas-liquid separator, and the hydrogen branch is used to transport the hydrogen generated by the electrolyzer; A circulating water loop, used to transport the water separated by the oxygen gas-liquid separator to the electrolyzer; A detection gas branch, used to pass a preset detection gas into the electrolyzer through the oxygen branch, or to pass the preset detection gas into the electrolyzer through the oxygen branch and the hydrogen branch; Among them, the inlet of the oxygen branch is connected to the oxygen outlet, the inlet of the hydrogen branch is connected to the first hydrogen outlet, the inlet of the circulating water loop is connected to the bottom outlet of the oxygen gas-liquid separator, the outlet of the circulating water loop is connected to the circulating water inlet, and the detection gas branch is connected to the bottom outlet of the oxygen gas-liquid separator and the bottom outlet of the hydrogen gas-liquid separator.

2. The system according to claim 1, It is characterized in that The electrolyzer is also provided with a second hydrogen outlet, and the system further comprises: a first emptying branch, used to discharge the preset detection gas entering the electrolytic cell at a first preset flow rate, the first emptying branch being connected to the circulating water inlet; a second exhaust branch, used to discharge the hydrogen entering the electrolyzer at a second preset flow rate, the second exhaust branch connecting the second hydrogen outlet and the hydrogen branch; The electrode detection device is connected to the bipolar plates of each chamber in the electrolytic cell and is used to perform preset detection on the membrane electrode of each chamber.

3. The system according to claim 2, It is characterized in that The first emptying branch includes a first three-way valve, a first flow regulating valve and a first flow meter, and the second emptying branch includes a second three-way valve, a second flow regulating valve and a second flow meter, wherein the first interface and the second interface of the first three-way valve are connected in series to the circulating water circuit, the third interface of the first three-way valve is emptied after passing through the first flow regulating valve and the first flow meter, the first interface of the second three-way valve is connected to the second hydrogen outlet, the second interface of the second three-way valve is connected to the hydrogen branch, and the third interface of the second three-way valve is emptied after passing through the second flow regulating valve and the second flow meter.

4. The system according to claim 1, It is characterized in that The oxygen branch also includes a first pressure regulating valve and a second pressure regulating valve, the hydrogen branch also includes a third pressure regulating valve and a fourth pressure regulating valve, and the detection gas branch includes a fifth pressure regulating valve and a third flow regulating valve, wherein the first pressure regulating valve and the second pressure regulating valve are respectively arranged at the inlet and outlet of the oxygen branch, the third pressure regulating valve and the fourth pressure regulating valve are respectively arranged at the inlet and outlet of the hydrogen branch, the outlet of the fifth pressure regulating valve and the inlet of the third flow regulating valve are connected to the bottom outlet of the oxygen gas-liquid separator, the outlet of the third flow regulating valve is connected to the bottom outlet of the hydrogen gas-liquid separator, and the inlet of the fifth pressure regulating valve is the input port of the preset detection gas.

5. The system according to claim 4, It is characterized in that The system further comprises: A heat exchanger comprising a first tube pass for conveying oxygen and a second tube pass for conveying circulating water; Wherein, the first pipe pass is arranged between the outlet of the first pressure regulating valve and the inlet of the oxygen gas-liquid separator, and the second pipe pass is connected in series to the circulating water loop.

6. The system according to claim 5, It is characterized in that The circulating water loop is provided with a circulating pump and a metal ion filter, the inlet of the second pipe side is the inlet of the circulating water loop, the outlet of the second pipe side is connected to the inlet of the circulating pump, the outlet of the circulating pump is connected to the inlet of the metal ion filter, and the outlet of the metal ion filter is the outlet of the circulating water loop.

7. The system of claim 1, It is characterized in that The system further comprises: A temperature sensor, used to detect the temperature of water in the oxygen gas-liquid separator; A temperature control unit is used to obtain the temperature from the temperature sensor and make the temperature within a preset temperature range.

8. A control method for a PEM electrolyzer hydrogen production system, It is characterized in that Applied in the PEM electrolyzer hydrogen production system according to any one of claims 1 to 7, the method comprises: Get the detection instruction; If the detection instruction is an internal leakage detection instruction, the system stops producing hydrogen, and discharges hydrogen and oxygen in the electrolyzer, the oxygen branch and the hydrogen branch, and then passes the preset detection gas into the oxygen gas-liquid separator based on the detection gas branch; adjusting a first gas pressure in the oxygen branch, and when the first gas pressure reaches a first preset pressure, passing the preset detection gas into the electrolytic cell based on the oxygen branch, and maintaining the pressure in the electrolytic cell; The internal leakage detection result is determined according to the pressure of the oxygen outlet, the pressure of the circulating water inlet and the pressure of the first hydrogen outlet.

9. The control method according to claim 8, It is characterized in that After obtaining the detection instruction, the method further includes: If the detection instruction is a leakage detection instruction, the system stops producing hydrogen, and discharges hydrogen and oxygen in the electrolyzer, the oxygen branch and the hydrogen branch, and then based on the detection gas branch, the preset detection gas is respectively introduced into the oxygen gas-liquid separator and the hydrogen gas-liquid separator; adjusting the first gas pressure, and when the first gas pressure reaches the first preset pressure, passing the preset detection gas into the electrolytic cell based on the oxygen branch, and maintaining the pressure in the electrolytic cell; adjusting the second gas pressure in the hydrogen branch, and when the second gas pressure reaches the first preset pressure, passing the preset detection gas into the electrolytic cell based on the hydrogen branch, and maintaining the pressure in the electrolytic cell; The leakage detection result is determined according to the pressure of the oxygen outlet, the pressure of the first hydrogen outlet and the pressure of the circulating water inlet.

10. The control method according to claim 9, It is characterized in that After obtaining the detection instruction, the method further includes: If the detection instruction is an electrode detection instruction, the system is started to produce hydrogen, and the hydrogen production is stopped after a preset time, and the oxygen in the oxygen branch is discharged, and then the preset detection gas is passed into the oxygen gas-liquid separator based on the detection gas branch; adjusting the first gas pressure so that the first gas pressure first reaches the first preset pressure and then decreases to a second preset pressure, and passing the preset detection gas into the electrolytic cell based on the oxygen branch; adjusting the second gas pressure so that the second gas pressure first reaches the first preset pressure and then decreases to the second preset pressure, and reversely passes hydrogen into the electrolyzer based on the hydrogen branch; The preset detection gas is discharged at the circulating water inlet at a first preset flow rate, and the hydrogen is discharged at the second hydrogen outlet on the electrolyzer at a second preset flow rate; An electrode detection device is started, and an electrode detection result is determined according to an output result of the electrode detection device, wherein the electrode detection device is connected to the bipolar plates of each chamber in the electrolytic cell.

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