Method and system for controlling separator liquid level during hydrogen production by water electrolysis

Abstract

The present invention relates to the technical field of electrolysis cell control. Disclosed are a method and system for controlling a separator liquid level during hydrogen production by water electrolysis. In the present invention, the separator liquid level is used as a primary variable, and the make-up water flow rate is used as a secondary variable, forming a cascade control system. In addition, the change values of an electrolysis system pressure, electrolysis cell power, and an alkaline solution temperature are used as feed-forward signals and are respectively input into feed-forward controllers. Output values are summed and then used, together with the cascade control system, to form a feed-forward-cascade control system. The control method can achieve precise control of the liquid level on a hydrogen side and the liquid level on an oxygen side, thereby avoiding the problem of an excessive difference in liquid level between the hydrogen side and the oxygen side caused by changes in the system pressure, the electrolysis cell power, the alkaline solution temperature, and the make-up water flow rate, avoiding the problem of equipment damage and even personal injuries resulting from the risk of explosion due to mixing of gases on two sides when the liquid levels are too low, and avoiding economic losses caused by protective shutdown triggered by high or low liquid level alarms.

Description

A method and system for controlling the liquid level in a separator during water electrolysis for hydrogen production. Technical Field

[0001] This invention belongs to the field of electrolyzer control technology, and specifically relates to a method and system for controlling the liquid level of a separator in the process of producing hydrogen by electrolysis of water. Background Technology

[0002] In the process of producing hydrogen by alkaline water electrolysis, it is usually necessary to control the liquid levels in the hydrogen-side separator and the oxygen-side separator, and ensure that the liquid level difference between the hydrogen-side separator and the oxygen-side separator is within a certain range to ensure the normal operation of the electrolysis process.

[0003] The existing liquid level control method involves manually operating the equipment before formal operation to maintain the oxygen-side liquid level within a certain range. During operation, the oxygen-side liquid level is controlled based on experience, with the number of water replenishment cycles set in the DCS / PLC controller. Replacement water is then supplied to both the hydrogen-side and oxygen-side separators to maintain the oxygen-side liquid level. Alternatively, a DCS / PLC can be used as the controller, employing a PID control algorithm. The oxygen-side liquid level is used as the setpoint, and the hydrogen-side liquid level as the actual value (feedback value). The PID output signal controls the liquid level regulating valve, ensuring the hydrogen-side liquid level follows the oxygen-side liquid level. This prevents the mixing of gases from both sides when the liquid level is too low, which could lead to an explosion or trigger a protective shutdown that would disrupt production.

[0004] However, the control accuracy of the above methods is not precise because the factors affecting the liquid level include multiple factors such as alkali temperature, electrolytic cell power, system pressure, and water replenishment rate. Alkali temperature and electrolytic cell power both affect system pressure, which in turn affects the oxygen-side liquid level. However, since the system pressure does not immediately reflect changes in alkali temperature and electrolytic cell power, directly controlling the liquid level using pressure is ineffective. Simply relying on PID control to directly control the liquid level cannot overcome the "false water level" caused by pressure changes, leading to controller malfunctions. The control action is also untimely (feedback control only takes effect after the disturbance has already had an impact, and the system suffers from capacity lag and pure lag), and it cannot overcome the disturbance caused by changes in water replenishment flow rate. If the liquid level is used as the control variable, and the changes in system pressure, electrolytic cell power, and alkali temperature (disturbances) are used as feedforward signals, the disturbance caused by changes in water replenishment flow rate cannot be overcome. If the liquid level is used as the primary variable and the water replenishment flow rate as the secondary variable, forming a cascade control system, it cannot overcome disturbances in system pressure, electrolytic cell power, and alkali temperature. In summary, it can be seen that none of the existing liquid level control methods can achieve precise control of the liquid level. Summary of the Invention

[0005] To address the above problems, in a first aspect, this invention proposes a method for controlling the liquid level in a separator during water electrolysis for hydrogen production. The control method includes the following steps:

[0006] Real-time data of electrolysis system pressure, electrolytic cell power, alkali solution temperature, separator liquid level, and separator set liquid level were acquired respectively.

[0007] The changes in the pressure of the electrolysis system, the power of the electrolytic cell, and the temperature of the alkali solution are used as the inputs of the corresponding feedforward controllers, and the first result is determined based on the output of the corresponding feedforward controllers.

[0008] The real-time data of the separator liquid level and the separator set liquid level are used together as the input of the main controller, and the second result is output.

[0009] The first and second results are added together to form the setpoint of the secondary controller. The water supply flow rate of the separator is used as the feedback value of the secondary controller. The setpoint and feedback value of the secondary controller are used together as the input of the secondary controller. The water supply flow rate is controlled according to the output signal of the secondary controller, thereby controlling the liquid level of the separator.

[0010] Furthermore, when controlling the liquid level of the oxygen-side separator, the pressure of the electrolysis system is the oxygen-side pressure of the oxygen-side separator, the liquid level of the separator is the actual liquid level of the oxygen-side separator, and the set liquid level of the separator is the set liquid level of the oxygen-side separator.

[0011] When controlling the liquid level of the hydrogen-side separator, the pressure of the electrolysis system is the hydrogen-side pressure of the hydrogen-side separator, the liquid level of the separator is the actual liquid level of the hydrogen-side separator, and the set liquid level of the separator is the set liquid level of the hydrogen-side separator.

[0012] Furthermore, the power of the electrolytic cell is calculated based on the real-time voltage and current of the power supply.

[0013] Furthermore, the temperature of the alkaline solution is measured using the oxygen-side outlet temperature of the electrolyzer.

[0014] Furthermore, the changes in the electrolysis system pressure, the electrolytic cell power, and the alkali solution temperature are used as inputs to the corresponding feedforward controllers. The first result is determined based on the output of the corresponding feedforward controllers, including:

[0015] The difference between two consecutive real-time pressure data of the electrolysis system is input into the pressure feedforward controller, and the first information is output.

[0016] The difference between two consecutive real-time power data of the electrolyzer is input into the power feedforward controller, and the second information is output.

[0017] The difference between two consecutive real-time data of alkaline solution temperature is input into the temperature feedforward controller, and the third information is output.

[0018] The first result is obtained by summing the first, second, and third information.

[0019] Furthermore, the feedforward controller and the secondary controller employ the P control algorithm, while the primary controller employs the PID control algorithm.

[0020] Secondly, this invention proposes a control system for the liquid level of a separator during the electrolysis of water to produce hydrogen, comprising:

[0021] The acquisition unit is used to acquire real-time data of electrolysis system pressure, electrolytic cell power, alkali temperature, separator liquid level and separator set liquid level, respectively.

[0022] The first result output unit is used to take the change value of the electrolysis system pressure, the change value of the electrolysis cell power, and the change value of the alkali solution temperature as the input of the corresponding feedforward controller, and determine the first result based on the output result of the corresponding feedforward controller.

[0023] The second result output unit is used to take the real-time data of the separator liquid level and the separator set liquid level as inputs to the main controller and output the second result.

[0024] The liquid level control unit is used to add the first result and the second result together as the set value of the sub-controller, and the separator water supply flow rate as the feedback value of the sub-controller. The set value and the feedback value of the sub-controller are used together as the input of the sub-controller. The water supply flow rate is controlled according to the output signal of the sub-controller, thereby controlling the liquid level of the separator.

[0025] Thirdly, the present invention proposes an electrolyzer hydrogen production system that includes a control system for the separator liquid level during the electrolysis of water to produce hydrogen.

[0026] Fourthly, the present invention proposes an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0027] Memory, which stores computer programs;

[0028] The processor, when executing the program stored in the memory, implements the method for controlling the liquid level of the separator in the process of producing hydrogen through water electrolysis.

[0029] Fifthly, the present invention provides a computer-readable storage medium storing a computer program, which, when run, executes the method for controlling the liquid level of the separator during the electrolysis of water to produce hydrogen.

[0030] The beneficial effects of this invention are:

[0031] This invention uses the separator liquid level as the primary variable and the makeup water flow rate as the secondary variable to form a cascade control system. Simultaneously, changes in the electrolysis system pressure, electrolyzer power, and alkali solution temperature are used as feedforward signals, input to the feedforward controller respectively. The output values ​​are summed and then combined with the cascade control system to form a feedforward-cascade control system. This control method can precisely control the hydrogen and oxygen side liquid levels, avoiding excessive level differences between the hydrogen and oxygen sides caused by variations in system pressure, electrolyzer power, alkali solution temperature, and makeup water flow rate. It also avoids the risk of explosion due to gas mixing at low liquid levels, which could damage equipment or even cause injury. Furthermore, it prevents economic losses caused by high / low liquid level alarms triggering protective shutdowns.

[0032] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0033] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 shows a flowchart of the alkaline water electrolysis process;

[0035] Figure 2 shows a flowchart of a method for controlling the liquid level of a separator during water electrolysis hydrogen production according to an embodiment of the present invention.

[0036] Figure 3 shows a block diagram of oxygen-side feedforward-cascade control in an embodiment of the present invention;

[0037] Figure 4 shows a block diagram of hydrogen-side feedforward-cascade control in an embodiment of the present invention;

[0038] Figure 5 shows a schematic diagram of an electronic device according to an embodiment of the present invention;

[0039] Figure descriptions: 1. Power supply; 2. Voltmeter; 3. Ammeter; 4. Electrolytic cell; 5. Temperature transmitter; 6. Hydrogen-side separator; 7. Hydrogen-side level transmitter; 8. First flow meter; 9. Level regulating valve; 10. Hydrogen-side water supply valve; 11. Oxygen-side separator; 12. Oxygen-side level transmitter; 13. Second flow meter; 14. Pressure transmitter; 15. Pressure regulating valve; 16. Oxygen-side water supply valve; 17. Water supply pump. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0041] The process flow diagram for hydrogen production by water electrolysis is shown in Figure 1. Electrolyzer 4 is powered by power supply 1. An alkaline inlet is provided on electrolyzer 4. The alkaline solution is electrolyzed in electrolyzer 4 to generate hydrogen and oxygen. The generated hydrogen and oxygen (mixed with alkaline solution) enter hydrogen-side separator 6 and oxygen-side separator 11 respectively for gas-liquid separation. The separated alkaline solution is returned to electrolyzer 4 to participate in the next electrolysis. The separated hydrogen and oxygen enter the purification system (not shown in the figure). Water not consumed by electrolysis is replenished by demineralized water (make-up water) to hydrogen-side separator 6 and oxygen-side separator 11 through a water pump, hydrogen-side water valve 10, and oxygen-side water valve 16 respectively. It should be noted that the complete process flow is as follows: the mixture from hydrogen-side separator 6 / oxygen-side separator 11 passes through hydrogen heat exchanger / oxygen heat exchanger, hydrogen scrubber / oxygen scrubber, hydrogen-side gas-liquid separator / oxygen-side gas-liquid separator before entering the purification system. After the alkali solution is refluxed, it passes through the heat exchanger and alkali solution circulation pump before entering the electrolytic cell 4. The demineralized water enters the hydrogen-side gas-liquid separator / oxygen-side gas-liquid separator and then refluxes back to hydrogen-side separator 6 / oxygen-side separator 11. The above process is not fully shown in Figure 1.

[0042] Based on the above-described water electrolysis hydrogen production process, this invention proposes a control system for the separator liquid level during water electrolysis hydrogen production, comprising:

[0043] The acquisition unit is used to acquire real-time data of electrolysis system pressure, electrolytic cell power, alkali temperature, separator liquid level and separator set liquid level, respectively.

[0044] The first result output unit is used to take the change value of the electrolysis system pressure, the change value of the electrolysis cell power, and the change value of the alkali solution temperature as the input of the corresponding feedforward controller, and determine the first result based on the output result of the corresponding feedforward controller.

[0045] The second result output unit is used to take the real-time data of the separator liquid level and the separator set liquid level as inputs to the main controller and output the second result.

[0046] The liquid level control unit is used to add the first result and the second result together as the set value of the sub-controller, and the separator water supply flow rate as the feedback value of the sub-controller. The set value and the feedback value of the sub-controller are used together as the input of the sub-controller. The water supply flow rate is controlled according to the output signal of the sub-controller, thereby controlling the liquid level of the separator.

[0047] In an exemplary embodiment of the present invention, the acquisition unit includes a pressure transmitter 14 for acquiring the pressure of the electrolysis system, an ammeter 3 for acquiring the current of the power supply 1, a voltmeter 2 for acquiring the voltage of the power supply 1, an oxygen-side temperature transmitter 5 for acquiring the temperature of the alkali solution, and an oxygen-side level transmitter 12 or a hydrogen-side level transmitter 7 for acquiring the liquid level of the separator. The first result output unit is a feedforward controller, the second result output unit is a main controller, and the liquid level control unit is a secondary controller.

[0048] In another exemplary embodiment of the present invention, a hydrogen production system for water electrolysis is proposed. The hydrogen production system includes a control system for the liquid level of the separator in the process of hydrogen production by water electrolysis mentioned in the above embodiment. Part of the structure can be set as shown in Figure 1. The hydrogen-side separator 6 is provided with a hydrogen mixing inlet, a hydrogen outlet, a hydrogen-side water replenishment inlet, a hydrogen-side alkali outlet, and a hydrogen-side liquid level transmitter 7. The oxygen mixing inlet is connected to the hydrogen outlet pipeline of the electrolyzer 4, and is used to transport the hydrogen from the mixed alkaline solution in the electrolyzer 4 to the hydrogen-side separator 6 for separation; the hydrogen outlet is connected to the hydrogen outlet pipeline, and a liquid level regulating valve 9 is installed on the hydrogen outlet pipeline to regulate the liquid level in the hydrogen-side separator 6; the hydrogen-side water inlet is connected to the hydrogen-side water supply pipeline, and a first flow meter 8 and a hydrogen-side water supply valve 10 are installed on the hydrogen-side water supply pipeline, and the first flow meter 8 collects the water supply flow of the hydrogen-side separator 6; the alkaline solution outlet is connected to the alkaline solution inlet pipeline of the electrolyzer 4, and is used to return the alkaline solution separated in the hydrogen-side separator 6 to the electrolyzer 4; the hydrogen-side liquid level transmitter 7 is used to collect the liquid level in the hydrogen-side separator 6.

[0049] The oxygen-side separator 11 is equipped with an oxygen mixing inlet, an oxygen outlet, an oxygen-side water supply inlet, an oxygen-side alkali outlet, and an oxygen-side liquid level transmitter 12. The oxygen mixing inlet is connected to the oxygen outlet pipeline of the electrolytic cell 4, and is used to transport the oxygen of the mixed alkaline solution in the electrolytic cell 4 to the oxygen-side separator 11 for separation. A temperature transmitter 5 is installed on the oxygen outlet pipeline of the electrolytic cell 4 to detect the temperature of the alkaline solution. The oxygen outlet is connected to the oxygen outlet pipeline, and a pressure transmitter 14 and a pressure regulating valve 15 are installed on the oxygen outlet pipeline to collect and regulate the system pressure. The oxygen-side water inlet is connected to the oxygen-side water supply pipeline, and a second flow meter 13 and an oxygen-side water supply valve 16 are installed on the oxygen-side water supply pipeline. The second flow meter 13 collects the water supply flow of the oxygen-side separator 11. The oxygen-side alkaline solution outlet is connected to the alkaline solution inlet pipeline of the electrolytic cell 4, and is used to return the alkaline solution separated in the oxygen-side separator 11 to the electrolytic cell 4. The oxygen-side liquid level transmitter 12 is used to collect the liquid level in the oxygen-side separator 11.

[0050] The hydrogen-side water supply valve 10 and the oxygen-side water supply valve 16 are connected to a water supply pump, which pumps demineralized water into the hydrogen-side water supply pipeline and / or the hydrogen-side water supply pipeline.

[0051] It should be noted that the type of power source 1 is not specifically limited in this invention, including wind power, photovoltaic power, or grid power. The power source 1 is equipped with a voltmeter 2 and an ammeter 3 to determine the power variation of the electrolytic cell. The feedforward controller, main controller, and auxiliary controller are not shown in Figure 1.

[0052] To address the aforementioned electrolysis process, this invention proposes a method for controlling the liquid level in water electrolysis for hydrogen production, as shown in Figure 2. The control method includes the following steps:

[0053] S1: Acquire real-time data of electrolysis system pressure, electrolytic cell power, alkali temperature, separator level and separator set level respectively;

[0054] S2: The changes in the pressure of the electrolysis system, the power of the electrolytic cell, and the temperature of the alkali solution are used as the inputs of the corresponding feedforward controllers, and the first result is determined based on the output of the corresponding feedforward controllers.

[0055] S3: Use the real-time data of the separator liquid level and the separator set liquid level as input to the main controller, and output the second result;

[0056] S4: The first result and the second result are added together as the set value of the secondary controller, and the water supply flow rate of the separator is used as the feedback value of the secondary controller. The set value and the feedback value of the secondary controller are used together as the input of the secondary controller. The water supply flow rate is controlled according to the output signal of the secondary controller, thereby controlling the liquid level of the separator.

[0057] It should be noted that the above method can control the liquid levels of the oxygen-side separator and the hydrogen-side separator. When controlling the liquid level of the oxygen-side separator, the electrolysis system pressure in step S1 is the oxygen-side pressure of oxygen-side separator 11, and the separator liquid level is the actual liquid level of oxygen-side separator 11. When controlling the liquid level of the hydrogen-side separator, the electrolysis system pressure is the hydrogen-side pressure of hydrogen-side separator 6, and the separator liquid level is the actual liquid level of hydrogen-side separator 6. The alkaline solution temperature is measured by the temperature transmitter 5 installed on the oxygen outlet pipeline of electrolytic cell 4, regardless of whether the liquid levels of the oxygen-side separator and the hydrogen-side separator are controlled. The electrolytic cell power is calculated based on the real-time voltage and current of power supply 1. The set liquid levels of the oxygen-side separator and the hydrogen-side separator can be set in the DCS / PLC controller of the electrolysis system.

[0058] In step S2, the changes in the electrolysis system pressure, the electrolytic cell power, and the alkali solution temperature are used as inputs to the corresponding feedforward controllers. Determining the first result based on the output of the corresponding feedforward controllers includes the following steps:

[0059] The difference between two consecutive real-time pressure data of the electrolysis system is input into the pressure feedforward controller, and the first information is output.

[0060] The difference between two consecutive real-time power data of the electrolyzer is input into the power feedforward controller, and the second information is output.

[0061] The difference between two consecutive real-time data of alkaline solution temperature is input into the temperature feedforward controller, and the third information is output.

[0062] The first result is obtained by summing the first, second, and third information.

[0063] The following description, using the control block diagram shown in Figure 3, illustrates an exemplary method for controlling the oxygen-side separator level during water electrolysis for hydrogen production. In this control process, the oxygen-side separator level L is used as the primary variable, and the makeup water flow rate F of oxygen-side separator 11 is used as the secondary variable, forming a cascade control system. The oxygen-side separator level and its setpoint x1 are used as inputs to the primary controller, with x2 as its output. Simultaneously, the changes (disturbances) in the electrolysis system pressure, electrolyzer power, and alkali temperature are input as feedforward signals to the feedforward controller. The outputs of these signals are summed to obtain x3, which, together with the cascade control system, forms an oxygen-side feedforward-cascade control system. The output x2 of the primary controller and x3 of the feedforward controller are added together to form the setpoint of the secondary controller, and the makeup water flow rate F is used as the feedback value. The setpoint and feedback value of the secondary controller are used as inputs to the secondary controller. Based on the output signal y1 of the secondary controller, the oxygen-side makeup water valve 16 is activated to control the makeup water flow rate, thereby achieving oxygen-side separator level control.

[0064] In the above process, the main controller uses a PID control algorithm to achieve precise control of the oxygen-side separator level, stabilizing the oxygen-side separator level above the set level x1. The set level x1 can be set in the DCS / PLC controller, and the level is acquired by the oxygen-side level transmitter 12. Through the integration of proportional (P), integral (I), and derivative (D) control actions, the proportional part outputs result x2 based on the magnitude of the error signal between the set level x1 and the oxygen-side separator level to reduce the error; the integral part integrates the error signal to eliminate steady-state error, ensuring that the oxygen-side separator level is stabilized at the set level x1; the derivative part differentiates the error signal to predict the error change trend and adjusts the output result x2 in advance, thereby adjusting the oxygen-side separator level and ensuring high control quality of the system.

[0065] The secondary controller uses the P control algorithm to quickly overcome the impact of fluctuations in the makeup water flow. The output result x2 of the main controller and the output result x3 of the feedforward controller are added together to form the setpoint of the secondary controller. The makeup water flow rate F of the oxygen-side separator is used as the feedback value of the secondary controller. The setpoint and feedback value of the secondary controller are used together as the input of the secondary controller. The output y1 of the secondary controller acts on the oxygen-side makeup water valve 16 to control the makeup water flow rate of the oxygen-side separator. The existence of the feedback value of the secondary controller reduces the accuracy requirements of the feedforward control model, improves the system's anti-disturbance capability, and has a certain degree of adaptive capability.

[0066] Feedforward controllers typically employ static feedforward, such as using a P-controller as the feedforward controller. Parameter tuning is completed during actual commissioning, allowing for early detection of changes in system pressure, electrolyzer power, and alkali temperature, thereby improving control quality. In one embodiment of the invention, the feedforward controller includes a pressure feedforward controller, a power feedforward controller, and a temperature feedforward controller. The output values ​​of these three controllers are summed to obtain x3. In other embodiments of the invention, the feedforward controller can also employ dynamic feedforward. The specific model needs to be determined based on the actual field conditions (dynamic characteristics of process interference channels and control channels). However, its structure is often complex and heavily reliant on the accuracy of model parameters, requiring specialized controllers or even computers for implementation, thus increasing the cost of the electrolysis system.

[0067] To control the hydrogen-side liquid level in the water electrolysis hydrogen production process, a PID control algorithm can be used, with the oxygen-side separator liquid level as the setpoint and the hydrogen-side separator liquid level as the actual value. Alternatively, a cascade control method can be used, with the hydrogen-side separator liquid level as the main variable and the hydrogen-side makeup water flow rate as the secondary variable. In an exemplary embodiment of the present invention, the same feedforward-cascade control method as the oxygen-side liquid level control is adopted, but the electrolysis system pressure is replaced with the hydrogen-side pressure of the hydrogen-side separator 6. In this control process, the hydrogen-side separator liquid level L is used as the main variable, and the makeup water flow rate F of the hydrogen-side separator 6 is used as the secondary variable, forming a hydrogen-side feedforward-cascade control (as shown in Figure 4). The hydrogen-side separator liquid level and the set liquid level x1 of the hydrogen-side separator 6 are used as inputs to the main controller, and the output result of the main controller is x2. At the same time, the changes in the electrolysis system pressure (hydrogen-oxygen side pressure of the hydrogen-side separator 6), the electrolyzer power, and the alkaline solution temperature are used as feedforward signals and input to the feedforward controller respectively. The output results of each are summed to obtain x3, which is then combined with the cascade control system to form a feedforward-cascade control system. The output result x2 of the main controller and the output result x3 of the feedforward controller are added together to form the set value of the secondary controller. The water supply flow rate F is used as the feedback value of the secondary controller. The set value and the feedback value of the secondary controller are used together as the input of the secondary controller. The output signal y1 of the secondary controller is applied to the hydrogen side water supply valve 10 to control the water supply flow rate, thereby realizing the liquid level control of the hydrogen side separator.

[0068] The above control process is a periodic dynamic cycle. In an exemplary embodiment of the present invention, the main controller, the secondary controller and the feedforward controller have a default operating cycle of 500ms, and each cycle starts from S1.

[0069] Another exemplary embodiment of the present invention provides an electronic device. As shown in FIG5, the electronic device includes at least one processor 501, at least one communication interface 502, at least one memory 503, and at least one communication bus 504; wherein, the processor 501, the communication interface 502, and the memory 503 communicate with each other through the communication bus 504;

[0070] Memory 503 stores computer programs;

[0071] The processor 501 is used to execute the program stored in the memory 503 to implement the method for controlling the liquid level of the separator in the process of producing hydrogen by electrolysis of water.

[0072] Optionally, the communication interface can be an interface of a communication module, such as the interface of a GSM module; the processor may be a CPU, an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The memory may include high-speed RAM and may also include non-volatile memory, such as at least one disk storage device. The memory stores a program, and the processor calls the program stored in the memory to execute some or all of the above-described method embodiments.

[0073] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when executed, implements some or all of the above-described method embodiments. Optionally, the storage medium may be a non-transitory computer-readable storage medium, such as a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0074] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling the liquid level in a separator during water electrolysis for hydrogen production, characterized in that, The control method includes the following steps: Real-time data of electrolysis system pressure, electrolytic cell power, alkali solution temperature, separator liquid level, and separator set liquid level were acquired respectively. The changes in the pressure of the electrolysis system, the power of the electrolytic cell, and the temperature of the alkali solution are used as the inputs of the corresponding feedforward controllers, and the first result is determined based on the output of the corresponding feedforward controllers. The real-time data of the separator liquid level and the separator set liquid level are used together as the input of the main controller, and the second result is output. The first and second results are added together to form the setpoint of the secondary controller. The water supply flow rate of the separator is used as the feedback value of the secondary controller. The setpoint and feedback value of the secondary controller are used together as the input of the secondary controller. The water supply flow rate is controlled according to the output signal of the secondary controller, thereby controlling the liquid level of the separator.

2. The method for controlling the liquid level of the separator in the process of hydrogen production by water electrolysis according to claim 1, characterized in that, When controlling the liquid level of the oxygen-side separator, the pressure of the electrolysis system is the oxygen-side pressure of the oxygen-side separator, the liquid level of the separator is the actual liquid level of the oxygen-side separator, and the set liquid level of the separator is the set liquid level of the oxygen-side separator. When controlling the liquid level of the hydrogen-side separator, the pressure of the electrolysis system is the hydrogen-side pressure of the hydrogen-side separator, the liquid level of the separator is the actual liquid level of the hydrogen-side separator, and the set liquid level of the separator is the set liquid level of the hydrogen-side separator.

3. The method for controlling the liquid level of the separator in the process of hydrogen production by water electrolysis according to claim 1, characterized in that, The power of the electrolytic cell is calculated based on the real-time voltage and current of the power supply.

4. The method for controlling the liquid level of the separator in the process of hydrogen production by water electrolysis according to claim 1, characterized in that, The temperature of the alkaline solution is measured using the oxygen-side outlet temperature of the electrolytic cell.

5. The method for controlling the liquid level of the separator in the process of hydrogen production by water electrolysis according to claim 1, characterized in that, The changes in the electrolysis system pressure, the electrolytic cell power, and the alkali solution temperature are used as inputs to the corresponding feedforward controllers. The first result is determined based on the output of the corresponding feedforward controllers, including: The difference between two consecutive real-time pressure data of the electrolysis system is input into the pressure feedforward controller, and the first information is output. The difference between two consecutive real-time power data of the electrolyzer is input into the power feedforward controller, and the second information is output. The difference between two consecutive real-time data of alkaline solution temperature is input into the temperature feedforward controller, and the third information is output. The first result is obtained by summing the first, second, and third information.

6. The method for controlling the liquid level of the separator in the process of hydrogen production by water electrolysis according to any one of claims 1-5, characterized in that, The feedforward controller and the secondary controller employ the P control algorithm, while the main controller employs the PID control algorithm.

7. A control system for the liquid level of a separator in a water electrolysis hydrogen production process, characterized in that, include: The acquisition unit is used to acquire real-time data of electrolysis system pressure, electrolytic cell power, alkali temperature, separator liquid level and separator set liquid level, respectively. The first result output unit is used to take the change value of the electrolysis system pressure, the change value of the electrolysis cell power, and the change value of the alkali solution temperature as the input of the corresponding feedforward controller, and determine the first result based on the output result of the corresponding feedforward controller. The second result output unit is used to take the real-time data of the separator liquid level and the separator set liquid level as inputs to the main controller and output the second result. The liquid level control unit is used to add the first result and the second result together as the set value of the sub-controller, and the separator water supply flow rate as the feedback value of the sub-controller. The set value and the feedback value of the sub-controller are used together as the input of the sub-controller. The water supply flow rate is controlled according to the output signal of the sub-controller, thereby controlling the liquid level of the separator.

8. An electrolyzer hydrogen production system, characterized in that, The hydrogen production system includes a control system for the separator liquid level during the water electrolysis hydrogen production process as described in claim 7.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, which stores computer programs; A processor, when executing a program stored in a memory, implements the method for controlling the liquid level of the separator in the process of producing hydrogen through water electrolysis as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is run, it executes the method for controlling the liquid level of the separator in the process of producing hydrogen by electrolysis of water as described in any one of claims 1-7.

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