Hydrogen production system and control method thereof

Abstract

The application provides a hydrogen production system and a control method thereof. The method comprises the following steps: obtaining the hydrogen-oxygen concentration of the hydrogen production system during normal operation of the hydrogen production system, wherein the hydrogen-oxygen concentration comprises the oxygen concentration in hydrogen and the hydrogen concentration in oxygen; when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, controlling the hydrogen production system to switch from the current working mode to an idle mode; controlling the hydrogen production system to switch from the idle mode to a shutdown mode according to the running time of the hydrogen production system in the idle mode, so as to control the electrolytic cell to shut down; and controlling the voltage of the electrolytic cell after the input electric parameter of the electrolytic cell is reduced to zero. In the scheme, when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, the hydrogen production system is made to enter the idle mode, so that the electrolytic cell is prevented from frequently shutting down, the number of times of shutting down of the electrolytic cell is reduced, the voltage of the electrolytic cell is controlled, the reverse current size and reverse current corrosion are inhibited, and the durability of the electrolytic cell is improved.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production system technology, and in particular to a hydrogen production system and its control method. Background Technology

[0002] With the increasing demand for hydrogen energy and the continuous reduction in the cost of electricity from new energy sources, the application scenarios for large-scale hydrogen production from new energy sources are becoming increasingly widespread.

[0003] In new energy hydrogen production systems, fluctuating and intermittent inputs are key factors testing the stability and reliability of the entire system, especially the electrolyzer. When shut down, the electrolyzer is in a capacitive state and undergoes a self-discharge process. Simultaneously, driven by the nickel-hydrogen active material at the bipolar anode, a galvanic cell effect is formed through the electrolyte connection, where a reduction reaction occurs at the anode and an oxidation reaction occurs at the cathode. Specifically, as follows... Figure 1 As shown, taking a small chamber as an example, Urev is the reversible electrolysis voltage, Rshunt is the electrolyte path impedance (bypass impedance), Re is the diaphragm electrode impedance, ηact is the electrode overpotential, and Ca is the double layer capacitance. When the electrolytic cell is shut down, reverse current is easily generated. Reverse current leads to cathode electrode decay, which seriously affects the life and durability of the electrolytic cell.

[0004] Therefore, in new energy hydrogen production systems, how to suppress the electrode decay caused by frequent shutdown of the electrolyzer, so as to reduce reverse current and reverse current corrosion and improve the durability of the electrolyzer, has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a hydrogen production system and its control method, which enables the hydrogen production system to enter an idle mode when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, thereby avoiding frequent shutdowns of the electrolyzer. By controlling the voltage of the electrolyzer, the magnitude of the reverse current is suppressed, reverse current corrosion is suppressed, and the durability of the electrolyzer is improved.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] The first aspect of this invention discloses a method for controlling a hydrogen production system, the method comprising:

[0008] During normal operation of the hydrogen production system, the hydrogen and oxygen concentrations of the hydrogen production system are obtained, and the hydrogen and oxygen concentrations include the oxygen concentration in hydrogen and the hydrogen concentration in oxygen.

[0009] When the oxygen concentration in the hydrogen exceeds the standard and the hydrogen concentration in the oxygen does not meet the standard, the hydrogen production system is controlled to switch from the current working mode to the idle mode.

[0010] Based on the operating time of the hydrogen production system in the idle mode, the hydrogen production system is controlled to switch from the idle mode to the shutdown mode, thereby controlling the electrolyzer to shut down;

[0011] After the input electrical parameters of the electrolytic cell are reduced to zero, the voltage of the electrolytic cell is controlled.

[0012] Optionally, when the oxygen concentration in the hydrogen exceeds the standard and the hydrogen concentration in the oxygen does not meet the standard, controlling the hydrogen production system to switch from the current operating mode to an idle mode includes:

[0013] When the oxygen concentration in the hydrogen is greater than the first preset hydrogen-oxygen concentration threshold and the hydrogen concentration in the oxygen is less than the second preset hydrogen-oxygen concentration threshold, it is determined that the oxygen concentration in the hydrogen exceeds the standard and the hydrogen concentration in the oxygen does not meet the standard, and it is determined that the hydrogen production system meets the preset idle mode conversion conditions.

[0014] The hydrogen production system is switched from its current operating mode to an idle mode.

[0015] Optionally, controlling the hydrogen production system to switch from the current operating mode to an idle mode includes:

[0016] Control the hydrogen production system to operate normally, and control the hydrogen production system to vent the hydrogen produced by the electrolyzer.

[0017] Optionally, controlling the hydrogen production system to switch from the idle mode to the shutdown mode based on the operating time of the hydrogen production system in the idle mode, thereby controlling the electrolyzer to shut down, includes:

[0018] The hydrogen production system is controlled to operate normally in the idle mode;

[0019] Obtain the normal operating time of the hydrogen production system in the idle mode;

[0020] When the normal operating time is greater than or equal to the preset idle time, it is determined that the hydrogen production system meets the preset shutdown mode switching conditions;

[0021] The hydrogen production system is switched from the idle mode to the shutdown mode to shut down the electrolyzer.

[0022] Optionally, after controlling the hydrogen production system to switch from the current operating mode to the idle mode, the method further includes:

[0023] The hydrogen production system is controlled to operate normally in the idle mode;

[0024] When the hydrogen concentration in the oxygen is greater than or equal to the third preset hydrogen-oxygen concentration threshold, it is determined that the hydrogen production system meets the preset shutdown mode conversion condition;

[0025] The hydrogen production system is switched from the idle mode to the shutdown mode to shut down the electrolyzer.

[0026] Optionally, the step of controlling the voltage of the electrolytic cell after the input electrical parameters of the electrolytic cell are reduced to zero includes:

[0027] Obtain the input electrical parameters of the electrolytic cell;

[0028] After the input electrical parameters of the electrolyzer are reduced to zero, the hydrogen production power supply or external power supply is controlled to enter the voltage control mode to control the voltage of the electrolyzer, so that the voltage of the electrolyzer decreases slowly.

[0029] The hydrogen production power supply or the external power supply is shut down based on the voltage of the electrolyzer and the voltage control time of the electrolyzer.

[0030] Optionally, obtaining the input electrical parameters of the electrolytic cell includes:

[0031] Obtain the input current and / or input power of the electrolytic cell;

[0032] Accordingly, after the input electrical parameters of the electrolyzer are reduced to zero, the hydrogen production power supply or external power supply is controlled to enter a voltage control mode to control the voltage of the electrolyzer, causing the voltage of the electrolyzer to decrease slowly, including:

[0033] When the input current and / or the input power decrease to zero, the hydrogen production power supply or external power supply is controlled to enter the voltage control mode to control the voltage of the electrolyzer, so that the voltage of the electrolyzer decreases slowly.

[0034] Optionally, controlling the shutdown of the hydrogen production power source or the external power source based on the voltage of the electrolyzer and the voltage control time of the electrolyzer includes:

[0035] When the voltage of the electrolyzer drops to a preset voltage and the voltage control time of the electrolyzer reaches a preset control time, the hydrogen production power supply or the external power supply is controlled to shut down.

[0036] Optionally, the step of controlling the hydrogen production power supply or the external power supply to shut down when the voltage of the electrolyzer drops to a preset voltage and the voltage control time of the electrolyzer reaches a preset control time includes:

[0037] The voltage of the electrolytic cell and the voltage control time of the electrolytic cell are obtained;

[0038] When the voltage of the electrolyzer is less than the preset voltage and the voltage control time of the electrolyzer is greater than the preset control time, the hydrogen production power supply or the external power supply is controlled to exit the voltage control mode and the hydrogen production power supply or the external power supply is controlled to shut down.

[0039] A second aspect of this invention discloses a hydrogen production system, comprising: a controller, a hydrogen production power supply, and an electrolyzer;

[0040] The output terminal of the hydrogen production power source is connected to the input terminal of the electrolyzer;

[0041] The controller is connected to the hydrogen production power source and the electrolyzer, respectively, and the controller is used to execute the hydrogen production system control method according to any one of the first aspects of the present invention.

[0042] Optionally, it also includes: an external power source; the external power source is connected between the output terminal of the hydrogen production power source and the input terminal of the electrolyzer.

[0043] Optionally, the external power supply may include a power converter.

[0044] A hydrogen production system and its control method provided by the above embodiments of the present invention include: during normal operation of the hydrogen production system, acquiring the hydrogen-oxygen concentration of the system, the hydrogen-oxygen concentration including the oxygen concentration in hydrogen and the hydrogen concentration in oxygen; when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, controlling the hydrogen production system to switch from the current operating mode to an idle mode; based on the operating time of the hydrogen production system in the idle mode, controlling the hydrogen production system to switch from the idle mode to a shutdown mode to control the electrolyzer to shut down; and after the input electrical parameters of the electrolyzer decrease to zero, performing voltage control on the electrolyzer. In this solution, when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, the hydrogen production system enters an idle mode, avoiding frequent shutdowns of the electrolyzer, thereby reducing the number of electrolyzer shutdowns. By controlling the voltage of the electrolyzer, the magnitude of reverse current and reverse current corrosion are suppressed, improving the durability of the electrolyzer. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of the structure of an electrolytic cell in the prior art, provided as an embodiment of the present invention;

[0047] Figure 2 A schematic flowchart of a hydrogen production system control method provided in an embodiment of the present invention;

[0048] Figure 3 A schematic flowchart of another hydrogen production system control method provided in an embodiment of the present invention;

[0049] Figure 4 This is a schematic diagram of a process for voltage control of an electrolytic cell provided in an embodiment of the present invention;

[0050] Figure 5 This is a schematic diagram of another process for voltage control of an electrolytic cell provided by an embodiment of the present invention;

[0051] Figure 6 A schematic diagram of a process for controlling the shutdown of a hydrogen production power source or an external power source, provided as an embodiment of the present invention;

[0052] Figure 7 This is a schematic diagram of a hydrogen production system provided in an embodiment of the present invention;

[0053] Figure 8 This is a schematic diagram of another hydrogen production system provided in an embodiment of the present invention. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] In this application, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0056] As can be seen from the background technology, in existing new energy hydrogen production systems, reverse current is easily generated when the electrolyzer is shut down. The reverse current causes the cathode electrode to decay, which seriously affects the life and durability of the electrolyzer.

[0057] Therefore, this invention provides a hydrogen production system and its control method. In this solution, when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, the hydrogen production system enters an idle mode to avoid frequent shutdowns of the electrolyzer, thereby reducing the number of times the electrolyzer is shut down. By controlling the voltage of the electrolyzer, the magnitude of the reverse current and reverse current corrosion are suppressed, thereby improving the durability of the electrolyzer.

[0058] like Figure 2 The diagram shown is a flowchart illustrating a hydrogen production system control method provided in an embodiment of the present invention.

[0059] It should be noted that this hydrogen production system control method is applied to hydrogen production systems. Specifically, it can be applied to the controller in the hydrogen production system used to execute control commands, or it can be applied to other controllers in the hydrogen production system.

[0060] It should also be noted that, in some cases, this hydrogen production system control method can also be applied to cloud servers or site-specific servers.

[0061] The control method for this hydrogen production system mainly includes the following steps:

[0062] Step S201: During the normal operation of the hydrogen production system, obtain the hydrogen and oxygen concentrations of the hydrogen production system.

[0063] In step S201, the hydrogen and oxygen concentrations can be used to measure the purity of hydrogen and oxygen in the electrolyzer.

[0064] The hydrogen-oxygen concentration includes, but is not limited to, the oxygen in hydrogen (OTH) concentration and the hydrogen in oxygen (HTO) concentration.

[0065] Oxygen in hydrogen (OTH) concentration refers to the concentration of oxygen in hydrogen in a hydrogen production system, and it characterizes the purity of hydrogen.

[0066] The hydrogen in oxygen (HTO) concentration refers to the concentration of hydrogen in oxygen in a hydrogen production system, and it characterizes the purity of oxygen.

[0067] In the specific implementation of step S201, during the normal operation of the hydrogen production system, a hydrogen-oxygen purity analyzer can be used to collect the actual oxygen concentration in hydrogen and the actual hydrogen concentration in oxygen in the electrolyzer of the hydrogen production system during the hydrogen production process.

[0068] In practical applications, a hydrogen-oxygen purity analyzer is used to detect the concentration of gases generated during the hydrogen production process in the electrolyzer of the hydrogen production system. Based on the detection results, a hydrogen-oxygen concentration curve can be established. The hydrogen-oxygen concentration curve can be used to characterize the correspondence between hydrogen-oxygen concentration (e.g., oxygen concentration in hydrogen and hydrogen concentration in oxygen) and the operating parameters of the hydrogen production system.

[0069] In some embodiments, the hydrogen-oxygen concentration curve can be used to characterize the correspondence between hydrogen-oxygen concentration and the input power of the hydrogen production system; or, the hydrogen-oxygen concentration curve can be used to characterize the correspondence between hydrogen-oxygen concentration and the input voltage of the hydrogen production system; or, the hydrogen-oxygen concentration curve can be used to characterize the correspondence between hydrogen-oxygen concentration and the input current of the hydrogen production system.

[0070] Step S202: If the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, proceed to step S203; otherwise, return to step S201.

[0071] In the specific implementation of step S202, the obtained hydrogen and oxygen concentrations are compared with preset safety thresholds. Specifically, the obtained oxygen concentration in hydrogen and hydrogen concentration in oxygen are compared with their respective preset safety thresholds. If the obtained oxygen concentration in hydrogen is greater than the corresponding preset safety threshold, it is determined that the obtained oxygen concentration in hydrogen exceeds the preset safety threshold, i.e., the obtained oxygen concentration in hydrogen exceeds the standard. If the obtained hydrogen concentration in oxygen is less than the corresponding preset safety threshold, it is determined that the obtained oxygen concentration in hydrogen does not exceed the preset safety threshold, i.e., the obtained oxygen concentration in hydrogen does not meet the standard. In other words, if the obtained oxygen concentration in hydrogen exceeds the standard and the obtained hydrogen concentration in oxygen does not meet the standard, it indicates that the relevant input of the hydrogen production system has large fluctuations and strong intermittency, and the hydrogen production system needs to be controlled. Then, step S203 is executed.

[0072] When the oxygen concentration in hydrogen or the hydrogen concentration in oxygen falls into any of the following categories, it indicates that the relevant input fluctuations of the hydrogen production system are small and the intermittency is weak, and there is no need to control the hydrogen production system. Then, step S201 is executed. The categories include: the oxygen concentration in hydrogen does not exceed the standard, and the hydrogen concentration in oxygen meets the standard; or, the oxygen concentration in hydrogen exceeds the standard, and the hydrogen concentration in oxygen meets the standard; or, the oxygen concentration in hydrogen does not exceed the standard, and the hydrogen concentration in oxygen does not meet the standard.

[0073] Step S203: Control the hydrogen production system to switch from the current working mode to the idle mode.

[0074] In step S203, the operating modes of the hydrogen production system include, but are not limited to, running mode, idle mode, and shutdown mode.

[0075] In operation mode, the hydrogen production system can perform electrolytic hydrogen production.

[0076] In idle mode, the hydrogen production system can perform electrolytic hydrogen production and vent the produced hydrogen. In practical applications, if the oxygen concentration in the hydrogen exceeds the standard and the hydrogen concentration in the oxygen does not meet the standard, the hydrogen production system will be controlled to enter idle mode.

[0077] In shutdown mode, the hydrogen production system stops performing electrolytic hydrogen production operations.

[0078] In the specific implementation of step S203, if it is determined that the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, it indicates that the input power of the hydrogen production system has decreased. The input power may be lower than the normal load of hydrogen production in the electrolyzer, and the hydrogen production system cannot meet the hydrogen production demand. First, it is necessary to switch the working mode of the hydrogen production system. Specifically, the current working mode of the hydrogen production system is determined according to the hydrogen and oxygen concentration, that is, the hydrogen production system is currently in the operating mode, and the hydrogen production system is controlled to switch from the operating mode to the idle mode.

[0079] Step S204: Based on the operating time of the hydrogen production system in idle mode, control the hydrogen production system to switch from idle mode to shutdown mode, so as to control the electrolyzer to shut down.

[0080] In the specific implementation of step S204, the hydrogen production system is controlled to operate normally in idle mode. The normal operating time T1 of the hydrogen production system in idle mode is collected by the timing device to determine whether it is necessary to switch the working mode of the hydrogen production system. If it is determined that it is necessary to switch the hydrogen production system to the shutdown mode, the hydrogen production system is controlled to switch from idle mode to shutdown mode to control the electrolyzer to shut down.

[0081] Step S205: After the input electrical parameters of the electrolytic cell are reduced to zero, the voltage of the electrolytic cell is controlled.

[0082] In step S205, the input electrical parameters include at least one of input current and input power.

[0083] The input current is the input current provided to the electrolyzer by the hydrogen production power source in the new energy hydrogen production system.

[0084] The input power is the power supplied to the electrolyzer by the hydrogen production power source in the new energy hydrogen production system.

[0085] Input electrical parameters include, but are not limited to, the electrolytic cell operating time and the electrolytic cell temperature.

[0086] The electrolyzer's operating time is the continuous operating time of the hydrogen production system.

[0087] The electrolyzer temperature is the actual operating temperature of the electrolyzer in the hydrogen production system.

[0088] In the specific implementation of step S205, after the hydrogen production system enters the shutdown mode, the hydrogen production power supply in the hydrogen production system is directly shut down. At this time, the detection device detects whether the input electrical parameters of the electrolyzer have decreased, and after the input electrical parameters of the electrolyzer have decreased to zero, the voltage of the electrolyzer is controlled.

[0089] According to the hydrogen production system control method provided by the embodiments of the present invention, when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, the hydrogen production system is put into an idle mode to avoid frequent shutdown of the electrolyzer, thereby reducing the number of shutdowns of the electrolyzer. By controlling the voltage of the electrolyzer, the magnitude of reverse current and reverse current corrosion are suppressed, thereby improving the durability of the electrolyzer.

[0090] Based on the hydrogen production system control method shown in the above embodiments of the present invention, such as Figure 3 The diagram shown is a flowchart of another hydrogen production system control method provided by an embodiment of the present invention, which mainly includes the following steps:

[0091] Step S301: During the normal operation of the hydrogen production system, obtain the hydrogen and oxygen concentrations of the hydrogen production system.

[0092] It should be noted that the execution principle and process of step S301 above are the same as those of... Figure 2 The execution principle and process of step S201 disclosed in the document are the same, and can be found in the document; they will not be repeated here.

[0093] Step S302: When the oxygen concentration in hydrogen is greater than the first preset hydrogen-oxygen concentration threshold and the hydrogen concentration in oxygen is less than the second preset hydrogen-oxygen concentration threshold, proceed to step S303; otherwise, return to step S301.

[0094] In step S302, the specific values ​​of the first preset hydrogen and oxygen concentration threshold k1 and the second preset hydrogen and oxygen concentration threshold k2 can be the same or different, depending on the actual situation of the electrolyzer. This application does not limit them, and they are all within the protection scope of this application.

[0095] In practical applications, the reasons that cause the oxygen concentration in hydrogen to be greater than the first preset hydrogen-oxygen concentration threshold k1 and / or the hydrogen concentration in oxygen to be less than the second preset hydrogen-oxygen concentration threshold k2 include, but are not limited to, a reduction in the input power of the hydrogen production system to the electrolyzer, or the input power may be lower than the normal load for hydrogen production in the electrolyzer, that is, the new energy power input to the electrolyzer is lower than the lower limit of the electrolyzer power.

[0096] In the specific implementation of step S302, if the oxygen concentration in hydrogen is greater than the first preset hydrogen-oxygen concentration threshold k1 and the hydrogen concentration in oxygen is less than the second preset hydrogen-oxygen concentration threshold k2, it indicates that the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard. The current input power of the hydrogen production system cannot meet the hydrogen production demand, and the hydrogen production system needs to be controlled. Then, step S303 is executed.

[0097] If the oxygen concentration in hydrogen is greater than the first preset hydrogen-oxygen concentration threshold k1 and the hydrogen concentration in oxygen is greater than the second preset hydrogen-oxygen concentration threshold k2, or if the oxygen concentration in hydrogen is less than the first preset hydrogen-oxygen concentration threshold k1 and the hydrogen concentration in oxygen is greater than the second preset hydrogen-oxygen concentration threshold k2, or if the oxygen concentration in hydrogen is less than the first preset hydrogen-oxygen concentration threshold k1 and the hydrogen concentration in oxygen is less than the second preset hydrogen-oxygen concentration threshold k2, then there is no need to control the hydrogen production system, and the process returns to step S301.

[0098] Step S303: Determine that the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, and determine that the hydrogen production system meets the preset idle mode conversion conditions.

[0099] In the specific implementation of step S303, if it is determined that the oxygen concentration in hydrogen is greater than the first preset hydrogen-oxygen concentration threshold k1 and the hydrogen concentration in oxygen is less than the second preset hydrogen-oxygen concentration threshold k2, it is determined that the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, and then it is determined that the hydrogen production system meets the preset idle mode conversion conditions.

[0100] Step S304: Control the hydrogen production system to switch from the current operating mode to the idle mode.

[0101] In the specific implementation of step S304, the current working mode of the hydrogen production system is determined based on the hydrogen and oxygen concentration, that is, the hydrogen production system is currently in the operating mode. After determining that the hydrogen production system meets the preset idle mode conversion conditions, the hydrogen production system is controlled to switch from the current operating mode to the idle mode.

[0102] Preferably, in some embodiments, the hydrogen production system can be switched from its current working mode to an idle mode by controlling the hydrogen production system to operate normally and controlling the hydrogen production system to vent the hydrogen produced by the electrolyzer.

[0103] In other words, the hydrogen production system enters an idle mode, operates normally in this mode, and vents the hydrogen produced by the electrolyzer, thereby reducing the number of times the electrolyzer is shut down.

[0104] Step S305: Control the hydrogen production system to operate normally in idle mode.

[0105] Step S306: Obtain the normal operating time of the hydrogen production system in idle mode.

[0106] In the specific implementation of step S306, the hydrogen production system is controlled to operate normally in idle mode, and a timing device is used to collect the normal operating time T1 of the hydrogen production system in idle mode.

[0107] Step S307: If the normal operating time is greater than or equal to the preset idle time, proceed to step S308; otherwise, return to step S305.

[0108] In step S307, the specific value of the preset idle time can be determined according to the actual situation of the hydrogen production system. This application does not limit it, and all of them are within the protection scope of this application.

[0109] In the specific implementation of step S307, the normal operating time T1 of the hydrogen production system in idle mode is compared with the preset idle time t1. If the normal operating time T1 of the hydrogen production system in idle mode is greater than the preset idle time t1, it means that the hydrogen production system is currently venting too much hydrogen, which is likely to cause excessive energy waste. It is necessary to control the hydrogen production system to stop the hydrogen venting operation and enter the shutdown mode, then step S308 is executed.

[0110] If the normal operating time T1 of the hydrogen production system in idle mode is less than or equal to the preset idle time t1, it means that the hydrogen production system still needs to release hydrogen to reduce the number of times the electrolyzer is shut down. In other words, it is still necessary to control the hydrogen production system to operate normally in idle mode, so step S305 is executed.

[0111] Step S308: Determine that the hydrogen production system meets the preset shutdown mode switching conditions.

[0112] In the specific implementation of step S308, if the running time T1 is determined to be greater than the preset time t1, the hydrogen production system is determined to meet the preset shutdown mode conversion conditions.

[0113] In addition to the methods described above for confirming that the hydrogen production system meets the preset shutdown mode switching conditions, the hydrogen concentration in oxygen can also be used to determine whether the hydrogen production system meets the preset shutdown mode switching conditions. This mainly includes the following steps:

[0114] Step S11: When the hydrogen concentration in oxygen is greater than or equal to the third preset hydrogen-oxygen concentration threshold, proceed to step S12; otherwise, return to step S305.

[0115] In step S11, the specific value of the third preset hydrogen and oxygen concentration threshold k3 can be determined according to the actual situation of the electrolyzer. This application does not limit it, and all of them are within the protection scope of this application.

[0116] In the specific implementation of step S11, the hydrogen concentration in oxygen is compared with the third preset hydrogen-oxygen concentration threshold k3. If the hydrogen concentration in oxygen is greater than or equal to the third preset hydrogen-oxygen concentration threshold k3, it means that the hydrogen production system needs to be controlled to stop the hydrogen venting operation and enter the shutdown mode, then step S12 is executed.

[0117] If the hydrogen concentration in oxygen is less than the third preset hydrogen-oxygen concentration threshold k3, it means that the hydrogen production system still needs to release hydrogen to reduce the number of times the electrolyzer is shut down. In other words, the hydrogen production system still needs to be controlled to operate normally in idle mode, so step S305 is executed.

[0118] Step S12: Determine that the hydrogen production system meets the preset shutdown mode switching conditions.

[0119] In the specific implementation of step S12, if the hydrogen concentration in oxygen is determined to be greater than or equal to the third preset hydrogen-oxygen concentration threshold k3, the hydrogen production system is determined to meet the preset shutdown mode conversion conditions.

[0120] Step S309: Control the hydrogen production system to switch from idle mode to shutdown mode in order to control the electrolyzer to shut down.

[0121] In the specific implementation of step S309, after determining that the hydrogen production system meets the preset shutdown mode conversion conditions, the hydrogen production system is controlled to switch from idle mode to shutdown mode, that is, the hydrogen production system is controlled to enter shutdown mode in order to control the electrolyzer to shut down.

[0122] Based on the above explanation, it can be understood that during normal operation of the hydrogen production system, when the concentration of oxygen (OTH) in hydrogen is greater than k1 and the concentration of hydrogen (HTO) in oxygen is less than k2, the hydrogen production system enters an idle mode: the hydrogen production system produces hydrogen normally and the generated hydrogen is vented; when the hydrogen production system operates in the idle mode for a time T1 ≥ t1, the hydrogen production system enters a shutdown mode and exits the idle mode to avoid excessive energy waste; or, when HTO ≥ k3, the hydrogen production system enters a shutdown mode.

[0123] In other words, considering the volatility and intermittency of new energy input and the possibility of frequent shutdowns, in this embodiment of the invention, an idle mode is added to the working mode of the hydrogen production system: the hydrogen concentration in oxygen does not exceed the standard, the hydrogen purity does not meet the standard, the hydrogen production system operates normally, the gas is vented, and some energy is sacrificed to minimize the number of times the electrolyzer is shut down.

[0124] It should be noted that the specific values ​​of k1, k2, t1, and k3 are determined according to the actual situation, and are not limited in this invention.

[0125] Step S310: After the input electrical parameters of the electrolytic cell are reduced to zero, the voltage of the electrolytic cell is controlled.

[0126] It should be noted that the execution principle and process of step S310 above are the same as those of... Figure 2 The execution principle and process of step S205 disclosed in the document are the same, and can be found therein, so they will not be repeated here.

[0127] According to the hydrogen production system control method provided by the embodiments of the present invention, when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, the hydrogen production system is put into an idle mode to avoid frequent shutdown of the electrolyzer, thereby reducing the number of shutdowns of the electrolyzer. By controlling the voltage of the electrolyzer, the magnitude of reverse current and reverse current corrosion are suppressed, thereby improving the durability of the electrolyzer.

[0128] Based on the hydrogen production system control method shown in the above embodiments of the present invention, the process of controlling the voltage of the electrolyzer after the input electrical parameters of the electrolyzer are reduced to zero in step S205 can be performed as follows: Figure 4 As shown, the main steps include:

[0129] Step S401: Obtain the input electrical parameters of the electrolytic cell.

[0130] In the specific implementation of step S401, a detection device is used to collect the input electrical parameters of the electrolytic cell (such as one or more electrical parameters such as input current, input power, and electrolytic cell temperature).

[0131] Step S402: After the input electrical parameters of the electrolyzer are reduced to zero, control the hydrogen production power supply or external power supply to enter the voltage control mode to control the voltage of the electrolyzer, so that the voltage of the electrolyzer decreases slowly.

[0132] In the specific implementation of step S402, after the input electrical parameters of the electrolyzer are reduced to zero, the hydrogen production power supply or external power supply is controlled to enter the voltage control mode. In the voltage control mode, the hydrogen production power supply or external power supply controls the voltage of the electrolyzer, thereby controlling the voltage of the electrolyzer to decrease slowly.

[0133] Step S403: Based on the voltage of the electrolyzer and the voltage control time of the electrolyzer, control the hydrogen production power supply or external power supply to shut down.

[0134] In the specific implementation of step S403, during the process of controlling the voltage of the electrolyzer to decrease slowly, a detection device is used to detect the voltage V of the electrolyzer in real time, and a timing device is used to collect the voltage control time T2 of the hydrogen production power supply or external power supply on the electrolyzer. Based on the voltage of the electrolyzer and the voltage control time of the electrolyzer, the hydrogen production power supply or external power supply is controlled to shut down.

[0135] Preferably, after the input electrical parameters of the electrolytic cell are reduced to zero in step S205, the process of controlling the voltage of the electrolytic cell can also be as follows: Figure 5 As shown, the main steps include:

[0136] Step S501: Obtain the input current and / or input power of the electrolytic cell.

[0137] In the specific implementation of step S501, a detection device is used to collect the input current and input power of the electrolytic cell.

[0138] Step S502: When the input current and / or input power decrease to zero, control the hydrogen production power supply or external power supply to enter the voltage control mode to control the voltage of the electrolyzer, so that the voltage of the electrolyzer decreases slowly.

[0139] In the specific implementation of step S502, when the input current and / or input power of the electrolyzer drops to zero, the hydrogen production power supply or external power supply is controlled to enter the voltage control mode. For example, voltage loop control is used. In the voltage control mode, the hydrogen production power supply or external power supply controls the voltage of the electrolyzer, thereby controlling the voltage of the electrolyzer to drop slowly.

[0140] Step S503: When the voltage of the electrolytic cell drops to the preset voltage and the voltage control time of the electrolytic cell reaches the preset control time, execute step S504; otherwise, return to execute step S502.

[0141] In the specific implementation of step S503, during the process of controlling the voltage of the electrolyzer to decrease slowly, a detection device is used to detect the voltage V of the electrolyzer in real time, and a timing device is used to count the voltage control time T2 of the hydrogen production power supply or external power supply on the electrolyzer. If the voltage V of the electrolyzer drops to the preset voltage V1, and the voltage control time T2 of the electrolyzer reaches the preset control time t2, it means that the reverse current can be controlled according to the voltage V of the electrolyzer, and the reverse current can be reduced. Then step S504 is executed.

[0142] If the voltage V of the electrolytic cell does not drop to the preset voltage V1, and the voltage control time T2 of the electrolytic cell does not reach the preset control time t2, or if the voltage V of the electrolytic cell drops to the preset voltage V1, but the voltage control time T2 of the electrolytic cell does not reach the preset control time t2, or if the voltage V of the electrolytic cell does not drop to the preset voltage V1, but the voltage control time T2 of the electrolytic cell reaches the preset control time t2, it indicates that the reverse current magnitude cannot be controlled according to the voltage V of the electrolytic cell at present, and voltage control of the electrolytic cell is still required to control the voltage of the electrolytic cell to drop slowly, then step S502 is executed.

[0143] Step S504: Control the hydrogen production power supply or external power supply to shut down.

[0144] In the specific implementation of step S504, when it is determined that the voltage of the electrolyzer drops to the preset voltage and the voltage control time of the electrolyzer reaches the preset time, the hydrogen production power supply or external power supply is shut down.

[0145] Preferably, the execution of step S503, where the voltage of the electrolyzer drops to a preset voltage and the voltage control time of the electrolyzer reaches a preset control time, and the process of controlling the hydrogen production power supply or external power supply to shut down in step S504, can be as follows: Figure 6 As shown, the main steps include:

[0146] Step S601: Obtain the voltage of the electrolytic cell and the voltage control time of the electrolytic cell.

[0147] In the specific implementation of step S601, during the process of controlling the voltage of the electrolyzer to decrease slowly, a detection device is used to detect the voltage of the electrolyzer in real time (the power source is the voltage of the electrolyzer after it decreases), and a timing device is used to collect the voltage control time of the electrolyzer by the hydrogen production power source or the external power source.

[0148] Step S602: When the voltage of the electrolytic cell is less than the preset voltage and the voltage control time of the electrolytic cell is greater than the preset control time, proceed to step S603; otherwise, return to step S502.

[0149] In the specific implementation of step S602, if the voltage V of the electrolytic cell drops to less than the preset voltage V1, and the voltage control time T2 of the electrolytic cell is greater than the preset control time t2, it means that the reverse current can be controlled according to the voltage V of the electrolytic cell, which can reduce the reverse current. Then step S603 is executed.

[0150] If the voltage V of the electrolytic cell does not drop below the preset voltage V1, and the voltage control time T2 of the electrolytic cell is not greater than the preset control time t2; or, the voltage V of the electrolytic cell drops below the preset voltage V1, but the voltage control time T2 of the electrolytic cell is not greater than the preset control time t2; or, the voltage V of the electrolytic cell does not drop below the preset voltage V1, but the voltage control time T2 of the electrolytic cell is greater than the preset control time t2, it indicates that the reverse current magnitude cannot be controlled according to the voltage V of the electrolytic cell, and voltage control of the electrolytic cell is still required. Then, step S502 is executed.

[0151] Step S603: Control the hydrogen production power supply or external power supply to exit the voltage control mode and control the hydrogen production power supply or external power supply to shut down.

[0152] In the specific implementation of step S603, when it is determined that the voltage of the electrolyzer drops to less than the preset voltage and the voltage control time of the electrolyzer is greater than the preset control time, the hydrogen production power supply or external power supply is controlled to stop controlling the voltage of the electrolyzer, the hydrogen production power supply or external power supply is controlled to exit the voltage control mode, and the hydrogen production power supply or external power supply is controlled to shut down.

[0153] Based on the above explanation, it can be understood that after the hydrogen production system enters shutdown mode, the hydrogen production power supply is directly shut down. When the input current or power of the electrolyzer drops to zero, the hydrogen production power supply or external power supply uses voltage mode control to slowly reduce the electrolyzer voltage. When the electrolyzer voltage V < V1 and the running time T2 > t2, the hydrogen production power supply or external power supply exits voltage control mode and shuts down. By controlling the form of the electrolyzer voltage, the magnitude of reverse current is suppressed, reverse current corrosion is inhibited, and the durability of the electrolyzer is improved.

[0154] In other words, after the hydrogen production system is shut down and the input current or input power of the electrolyzer reaches zero, the hydrogen production power supply or other external power supply controls the voltage of the electrolyzer to slowly reduce the voltage of the electrolyzer, thereby controlling the magnitude of the reverse current and minimizing the reverse current to inhibit reverse current corrosion.

[0155] According to the hydrogen production system control method provided by the embodiments of the present invention, when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, the hydrogen production system is put into an idle mode to avoid frequent shutdown of the electrolyzer, thereby reducing the number of shutdowns of the electrolyzer. By controlling the voltage of the electrolyzer, the magnitude of reverse current and reverse current corrosion are suppressed, thereby improving the durability of the electrolyzer.

[0156] Compared with the above embodiments of the present invention Figure 2 Corresponding to the hydrogen production system control method shown, this embodiment of the invention also provides a hydrogen production system, such as... Figure 7 As shown, the hydrogen production system includes: a controller, a hydrogen production power supply, an electrolyzer, and a gas-liquid separation and purification system.

[0157] The output of the hydrogen production power source is connected to the input of the electrolyzer.

[0158] The output of the electrolyzer is connected to the gas-liquid separation and purification system.

[0159] The controller is connected to the hydrogen production power source, the electrolyzer, and the gas-liquid separation and purification system, and executes the hydrogen production system control method described in any of the above-mentioned items.

[0160] The hydrogen production power source provides the energy for the hydrogen production system. The hydrogen production power source includes a power supply and a corresponding converter. The power supply can be the power grid, wind power, photovoltaic power, etc.

[0161] Preferably, the hydrogen production power source may also include an energy storage battery, making the output of the hydrogen production power source smoother and more stable.

[0162] Preferably, the controller obtains the hydrogen and oxygen concentrations of the hydrogen production system and related system parameter values ​​through communication messages.

[0163] Preferably, the electrolyzer can be an alkaline electrolyzer or a PEM (Proton Exchange Membrane) electrolyzer, depending on the actual needs, and the present invention does not limit it.

[0164] Preferably, based on the above Figure 7 The hydrogen production system shown combines Figure 7 ,like Figure 8 As shown, the hydrogen production system is further equipped with an external power source.

[0165] An external power supply is connected between the output terminal of the hydrogen production power supply and the input terminal of the electrolyzer.

[0166] An external power source is used to provide the energy for hydrogen production in the hydrogen production system.

[0167] It should be noted that the external power supply is an optional configuration and can be configured or not, depending on the actual situation.

[0168] Preferably, the external power supply includes a power converter.

[0169] Based on the hydrogen production system provided by the embodiments of the present invention, during the process of the controller executing the hydrogen production system control method described above, when the oxygen concentration in hydrogen exceeds the standard and the hydrogen concentration in oxygen does not meet the standard, the hydrogen production system enters an idle mode to avoid frequent shutdown of the electrolyzer, thereby reducing the number of electrolyzer shutdowns. By controlling the voltage of the electrolyzer, the magnitude of reverse current and reverse current corrosion are suppressed, thereby improving the durability of the electrolyzer.

[0170] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0171] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0172] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of controlling a hydrogen production system, the method comprising: The method comprises: During normal operation of the hydrogen production system, obtaining a hydrogen-oxygen concentration of the hydrogen production system, the hydrogen-oxygen concentration comprising a hydrogen-in-oxygen concentration and an oxygen-in-hydrogen concentration; When the hydrogen-in-oxygen concentration exceeds a standard and the oxygen-in-hydrogen concentration fails to meet a standard, controlling the hydrogen production system to switch from a current working mode to an idle mode, the hydrogen production system being configured to perform an electrolytic hydrogen production operation in the idle mode and venting the produced hydrogen gas; According to a running time of the hydrogen production system in the idle mode, controlling the hydrogen production system to switch from the idle mode to a shutdown mode to control the electrolytic cell to shut down; After an input electric parameter of the electrolytic cell is reduced to zero, performing voltage control on the electrolytic cell.

2. The method of claim 1, wherein, The controlling, when the hydrogen-in-oxygen concentration exceeds a standard and the oxygen-in-hydrogen concentration fails to meet a standard, the hydrogen production system to switch from a current working mode to an idle mode, comprises: When the hydrogen-in-oxygen concentration is greater than a first preset hydrogen-oxygen concentration threshold and the oxygen-in-hydrogen concentration is less than a second preset hydrogen-oxygen concentration threshold, determining that the hydrogen-in-oxygen concentration exceeds a standard and the oxygen-in-hydrogen concentration fails to meet a standard, and determining that the hydrogen production system meets a preset idle mode switching condition; Controlling the hydrogen production system to switch from a current working mode to an idle mode.

3. The method of claim 1, wherein, The controlling, according to a running time of the hydrogen production system in the idle mode, the hydrogen production system to switch from the idle mode to a shutdown mode to control the electrolytic cell to shut down, comprises: Controlling the hydrogen production system to normally run in the idle mode; Obtaining a normal running time of the hydrogen production system in the idle mode; When the normal running time is greater than or equal to a preset idle time, determining that the hydrogen production system meets a preset shutdown mode switching condition; Controlling the hydrogen production system to switch from the idle mode to a shutdown mode to control the electrolytic cell to shut down.

4. The method of claim 1, wherein, After the controlling, the hydrogen production system to switch from a current working mode to an idle mode, the method further comprises: Controlling the hydrogen production system to normally run in the idle mode; When the oxygen-in-hydrogen concentration is greater than or equal to a third preset hydrogen-oxygen concentration threshold, determining that the hydrogen production system meets a preset shutdown mode switching condition; Controlling the hydrogen production system to switch from the idle mode to the shutdown mode to control the electrolytic cell to shut down.

5. The method of claim 1, wherein, The performing, after an input electric parameter of the electrolytic cell is reduced to zero, voltage control on the electrolytic cell, comprises: Obtaining an input electric parameter of the electrolytic cell; After the input electric parameter of the electrolytic cell is reduced to zero, controlling a hydrogen production power supply or an additional power supply to enter a voltage control mode to perform voltage control on the electrolytic cell, so that the voltage of the electrolytic cell slowly decreases; According to the voltage of the electrolytic cell and a voltage control time of the electrolytic cell, controlling the hydrogen production power supply or the additional power supply to shut down.

6. The method of claim 5, wherein, The obtaining, the input electric parameter of the electrolytic cell, comprises: Obtaining an input current and / or an input power of the electrolytic cell; Correspondingly, the controlling, after the input electric parameter of the electrolytic cell is reduced to zero, the hydrogen production power supply or the additional power supply to enter a voltage control mode to perform voltage control on the electrolytic cell, so that the voltage of the electrolytic cell slowly decreases, comprises: When the input current and / or the input power decrease to zero, the hydrogen production power supply or the external power supply is controlled to enter a voltage control mode to control the voltage of the electrolytic cell, so that the voltage of the electrolytic cell slowly decreases.

7. The method of claim 5, wherein, The method for controlling the hydrogen production system according to the voltage of the electrolytic cell and the voltage control time of the electrolytic cell comprises: When the voltage of the electrolytic cell decreases to a preset voltage and the voltage control time of the electrolytic cell reaches a preset control time, the hydrogen production power supply or the external power supply is controlled to be turned off.

8. The method of claim 7, wherein, The method for controlling the hydrogen production system according to the voltage of the electrolytic cell and the voltage control time of the electrolytic cell comprises: The voltage of the electrolytic cell and the voltage control time of the electrolytic cell are obtained. When the voltage of the electrolytic cell is less than a preset voltage and the voltage control time of the electrolytic cell is greater than a preset control time, the hydrogen production power supply or the external power supply is controlled to exit the voltage control mode, and the hydrogen production power supply or the external power supply is controlled to be turned off.

9. A hydrogen production system, characterized by, The method for controlling the hydrogen production system comprises: A controller, a hydrogen production power supply and an electrolytic cell; An output end of the hydrogen production power supply is connected to an input end of the electrolytic cell; The controller is connected to the hydrogen production power supply and the electrolytic cell respectively, and is used to execute the method for controlling the hydrogen production system according to any one of claims 1-8.

10. The hydrogen production system of claim 9, wherein, The method for controlling the hydrogen production system further comprises: An external power supply connected between the output end of the hydrogen production power supply and the input end of the electrolytic cell.

11. The hydrogen production system of claim 10, wherein, The external power supply comprises a power converter.

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