A method and system for controlling the liquid level of a separator during the electrolytic water hydrogen production process

Abstract

The present invention discloses a method and system for controlling the liquid level of a separator during the electrolytic water hydrogen production process, belonging to the technical field of electrolytic cell control. In the present invention, the liquid level of the separator is used as the main variable and the water replenishment flow rate is used as the secondary variable to form a cascade control system. At the same time, the change values of the electrolysis system pressure, the electrolytic cell power, and the alkali liquor temperature are used as feedforward signals and respectively input into a feedforward controller. After the output values are summed, they are combined with the cascade control system to form a feedforward-cascade control system. The above control method can accurately control the liquid level on the hydrogen side and the oxygen side, avoid the problem of excessive liquid level difference between the hydrogen side and the oxygen side caused by changes in the system pressure, the electrolytic cell power, the alkali liquor temperature, and the water replenishment flow rate, and can also avoid the problem of gas mixing on both sides and the resulting explosion risk causing equipment damage or even personal injury when the liquid level is too low. It can also avoid the economic losses caused by the triggering of the liquid level high or low alarm to protect the shutdown.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrolytic cell control, and particularly relates to a method and system for controlling the liquid level of a separator during the process of hydrogen production by electrolyzing water. Background Art

[0002] In the process of alkaline water electrolysis for hydrogen production, 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 is as follows: Before the formal operation, the equipment is manually operated to make the oxygen-side liquid level within a certain range. During the operation, the control of the oxygen-side liquid level is based on experience. The number of water replenishment times is set in the DCS / PLC controller, and water is alternately replenished into the hydrogen-side separator and the oxygen-side separator to maintain the oxygen-side liquid level. Or use DCS / PLC as the controller, adopt the PID control algorithm, take the oxygen-side liquid level as the set value, the hydrogen-side liquid level as the actual value (feedback value), and the PID output signal to control the liquid level regulating valve, so that the hydrogen-side liquid level follows the oxygen-side liquid level, avoiding the explosion risk caused by the gas mixing on both sides when the liquid level is too low, or triggering the protection shutdown and affecting the production.

[0004] However, the control accuracy of the above control method is not accurate because the influencing factors of the liquid level include multiple factors such as the alkali liquor temperature, the electrolytic cell power, the system pressure, and the water replenishment speed. The alkali liquor temperature and the electrolytic cell power will both affect the system pressure, and then affect the oxygen-side liquid level. However, through links such as the electrolytic cell in the middle, when the alkali liquor temperature and the electrolytic cell power change, the system pressure cannot immediately reflect the pressure change. Therefore, directly controlling the liquid level with pressure has a poor effect. And simply relying on PID to directly control the liquid level cannot overcome the "false water level" caused by the pressure change, resulting in misoperation of the controller, and the control action is not timely (feedback control takes effect after the interference has formed an impact, and there is capacity lag and pure lag in the system), and it cannot overcome the interference brought by the change of the water replenishment flow rate. If the liquid level is used as the control variable and the change values (disturbance quantities) of the system pressure, the electrolytic cell power, and the alkali liquor temperature are used as the feedforward signals, the interference brought by the change of the water replenishment flow rate cannot be overcome. If the liquid level is used as the main variable and the water replenishment flow rate is used as the secondary variable to form a cascade control system, the disturbances of the system pressure, the electrolytic cell power, and the alkali liquor temperature cannot be overcome. In summary, it can be seen that the existing liquid level control methods cannot achieve precise control of the liquid level. Summary of the Invention

[0005] In view of the above problems, on the first aspect, the present invention proposes a method for controlling the liquid level of a separator during the process of hydrogen production by electrolyzing water. The control method includes the following steps:

[0006] Obtain the real-time data of the electrolysis system pressure, electrolyzer power, lye temperature, separator liquid level, and separator set liquid level respectively;

[0007] Take the change values of the electrolysis system pressure, electrolyzer power, and lye temperature as the inputs of the corresponding feedforward controllers respectively, and determine the first result according to the output results of the corresponding feedforward controllers;

[0008] Take the real-time data of the separator liquid level and the separator set liquid level as the input of the main controller, and output the second result;

[0009] Add the first result and the second result as the set value of the secondary controller, take the separator makeup water flow rate as the feedback value of the secondary controller, take the set value and the feedback value of the secondary controller as the input of the secondary controller, and control the makeup water flow rate according to the output signal of the secondary controller, so as to control the separator liquid level.

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

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

[0012] Further, the electrolyzer power is calculated according to the real-time voltage and current of the power supply.

[0013] Further, the lye temperature is measured by the oxygen-side outlet thermometer of the electrolyzer.

[0014] Further, taking the change values of the electrolysis system pressure, electrolyzer power, and lye temperature as the inputs of the corresponding feedforward controllers respectively, and determining the first result includes:

[0015] Input the difference between two adjacent real-time data of the electrolysis system pressure into the pressure feedforward controller, and output the first information;

[0016] Input the difference between two adjacent real-time data of the electrolyzer power into the power feedforward controller, and output the second information;

[0017] Input the difference between two adjacent real-time data of the lye temperature into the temperature feedforward controller, and output the third information;

[0018] Sum up the first information, the second information, and the third information to obtain the first result.

[0019] Further, the feedforward controller and the secondary controller adopt a P control algorithm, and the primary controller adopts a PID control algorithm.

[0020] In a second aspect, the present invention proposes a control system for the liquid level of a separator in the process of electrolytic water hydrogen production, including:

[0021] An acquisition unit for respectively acquiring real-time data of the electrolysis system pressure, the electrolytic cell power, the lye temperature, the separator liquid level, and the separator set liquid level;

[0022] A first result output unit for respectively using the change value of the electrolysis system pressure, the change value of the electrolytic cell power, and the change value of the lye temperature as inputs to the corresponding feedforward controllers, and determining a first result according to the output results of the corresponding feedforward controllers;

[0023] A second result output unit for jointly using the real-time data of the separator liquid level and the separator set liquid level as inputs to the primary controller and outputting a second result;

[0024] A liquid level control unit for adding the first result and the second result as the set value of the secondary controller, using the separator water replenishment flow rate as the feedback value of the secondary controller, jointly using the set value of the secondary controller and the feedback value of the secondary controller as inputs to the secondary controller, and controlling the water replenishment flow rate according to the output signal of the secondary controller, thereby controlling the separator liquid level.

[0025] In a third aspect, the present invention proposes an electrolytic cell hydrogen production system including the control system for the liquid level of a separator in the process of electrolytic water hydrogen production.

[0026] In a fourth aspect, the present invention proposes an electronic device, including a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete mutual communication through the communication bus;

[0027] The memory stores a computer program;

[0028] The processor, when executing the program stored in the memory, implements the control method for the liquid level of a separator in the process of electrolytic water hydrogen production.

[0029] In a fifth aspect, the present invention proposes a computer-readable storage medium storing a computer program, and when the computer program is run, it executes the control method for the liquid level of a separator in the process of electrolytic water hydrogen production.

[0030] The beneficial effects of the present invention:

[0031] In the present invention, the liquid level of the separator is used as the main variable, and the makeup water flow rate is used as the secondary variable to form a cascade control system. At the same time, the change values of the electrolysis system pressure, the electrolyzer power, and the lye temperature are used as feedforward signals and respectively input into the feedforward controller. After the output values are summed, they are combined with the cascade control system to form a feedforward-cascade control system. The above control method can accurately control the liquid levels on the hydrogen side and the oxygen side, avoid the problem of excessive liquid level difference between the hydrogen side and the oxygen side caused by changes in the system pressure, the electrolyzer power, the lye temperature, and the makeup water flow rate, and can also avoid the problem of gas mixing on both sides and explosion risk when the liquid level is too low, resulting in equipment damage or even casualties. It can also avoid the economic losses caused by the trigger of the liquid level high or low alarm to protect the shutdown.

[0032] Other features and advantages of the present invention will be described in the following specification, and part of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification, the claims, and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 Shows a flowchart of the alkaline electrolyzed water process;

[0035] Figure 2 Shows a flowchart of a control method for the liquid level of the separator during the electrolytic hydrogen production process proposed in the embodiment of the present invention;

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

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

[0038] Figure 5 Shows a schematic diagram of an electronic device in the embodiment of the present invention;

[0039] Brief Description of the Drawings: 1. Power supply; 2. Voltmeter; 3. Ammeter; 4. Electrolyzer; 5. Temperature transmitter; 6. Hydrogen-side separator; 7. Hydrogen-side liquid level transmitter; 8. First flowmeter; 9. Liquid level regulating valve; 10. Hydrogen-side water make-up valve; 11. Oxygen-side separator; 12. Oxygen-side liquid level transmitter; 13. Second flowmeter; 14. Pressure transmitter; 15. Pressure regulating valve; 16. Oxygen-side water make-up valve; 17. Feed water pump. Detailed Embodiments

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] The process flow diagram of hydrogen production by electrolyzing water is as Figure 1 shown. The electrolyzer 4 is powered by the power supply 1. An alkali liquor inlet is provided on the electrolyzer 4. In the electrolyzer 4, the alkali liquor is electrolyzed to generate hydrogen and oxygen. The generated hydrogen and oxygen (mixed with alkali liquor) respectively enter the hydrogen-side separator 6 and the oxygen-side separator 11 for gas-liquid separation. The separated alkali liquor flows back to the electrolyzer 4 to participate in the next electrolysis; the separated hydrogen and oxygen respectively enter the purification system (not shown in the figure). To supplement the water consumed by electrolysis, demineralized water (make-up water) is respectively supplemented into the hydrogen-side separator 6 and the oxygen-side separator 11 through the feed water pump, the hydrogen-side water make-up valve 10, and the oxygen-side water make-up valve 16. It should be noted that the complete process flow is that the mixtures coming out of the hydrogen-side separator 6 / oxygen-side separator 11 respectively pass through the hydrogen heat exchanger / oxygen heat exchanger, the hydrogen scrubber / oxygen scrubber, the hydrogen-side gas-water separator / oxygen-side gas-water separator and then enter the purification system. After the alkali liquor flows back, it enters the electrolyzer 4 after passing through the heat exchanger and the alkali liquor circulation pump. The demineralized water enters the hydrogen-side gas-liquid separator / oxygen-side gas-liquid separator and then flows back to the hydrogen-side separator 6 / oxygen-side separator 11. Figure 1 The above process is not fully shown in

[0042] Based on the above hydrogen production by electrolyzing water process flow, the present invention proposes a control system for the liquid level of the separator during hydrogen production by electrolyzing water, including:

[0043] An acquisition unit for respectively acquiring real-time data of the electrolysis system pressure, the electrolyzer power, the alkali liquor temperature, the separator liquid level, and the separator set liquid level;

[0044] The first result output unit is configured to use the change value of the electrolysis system pressure, the change value of the electrolyzer power, and the change value of the lye temperature as the inputs of the corresponding feedforward controllers respectively, and determine the first result according to the output results of the corresponding feedforward controllers;

[0045] The second result output unit is configured to use the real-time data of the separator liquid level and the separator set liquid level as the input of the main controller and output the second result;

[0046] The liquid level control unit is configured to use the sum of the first result and the second result as the set value of the secondary controller, and the separator make-up water flow rate as the feedback value of the secondary controller. The set value and the feedback value of the secondary controller are used as the inputs of the secondary controller together, and the make-up water flow rate is controlled according to the output signal of the secondary controller, so as to control the separator liquid level.

[0047] In an exemplary embodiment of the present invention, the acquisition unit includes a pressure transmitter 14 for collecting the electrolysis system pressure, an ammeter 3 for collecting the current of power supply 1, a voltmeter 2 for collecting the voltage of power supply 1, an oxygen-side temperature transmitter 5 for collecting the lye temperature, and an oxygen-side liquid level transmitter 12 or a hydrogen-side liquid level transmitter 7 for collecting the separator liquid level. 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, an electrolytic water hydrogen production system is proposed. The hydrogen production system includes the control system for the separator liquid level in the electrolytic water hydrogen production process mentioned in the above embodiment, and some structures can be as Figure 1 set. A hydrogen mixing inlet, a hydrogen outlet, a hydrogen-side make-up water inlet, a hydrogen-side lye outlet, and a hydrogen-side liquid level transmitter 7 are provided on the hydrogen-side separator 6. The oxygen mixing inlet is connected to the hydrogen outlet pipeline of the electrolyzer 4 for transporting the hydrogen in the mixed lye 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 for regulating the liquid level in the hydrogen-side separator 6; the hydrogen-side make-up water inlet is connected to the hydrogen-side make-up water pipeline, and a first flowmeter 8 and a hydrogen-side make-up water valve 10 are provided on the hydrogen-side make-up water pipeline. The first flowmeter 8 collects the make-up water flow rate of the hydrogen-side separator 6; the lye outlet is connected to the lye inlet pipeline of the electrolyzer 4 for returning the lye separated from the hydrogen-side separator 6 to the electrolyzer 4; the hydrogen-side liquid level transmitter 7 is used for collecting the liquid level in the hydrogen-side separator 6.

[0049] An oxygen-side separator 11 is provided with an oxygen mixing inlet, an oxygen outlet, an oxygen-side water replenishment port, an oxygen-side lye outlet, and an oxygen-side liquid level transmitter 12. The oxygen mixing inlet is connected to the oxygen outlet pipeline of the electrolyzer 4 for transporting the oxygen in the mixed lye in the electrolyzer 4 to the oxygen-side separator 11 for separation. A temperature transmitter 5 is provided on the oxygen outlet pipeline of the electrolyzer 4 for detecting the lye temperature; the oxygen outlet is connected to an oxygen outlet pipeline, and a pressure transmitter 14 and a pressure regulating valve 15 are installed on the oxygen outlet pipeline for collecting and regulating the system pressure; the oxygen-side water replenishment port is connected to an oxygen-side water replenishment pipeline, and a second flowmeter 13 and an oxygen-side water replenishment valve 16 are provided on the oxygen-side water replenishment pipeline. The second flowmeter 13 collects the water replenishment flow rate of the oxygen-side separator 11; the oxygen-side lye outlet is connected to the lye inlet pipeline of the electrolyzer 4 for returning the lye separated in the oxygen-side separator 11 to the electrolyzer 4; the oxygen-side liquid level transmitter 12 is used for collecting the liquid level in the oxygen-side separator 11.

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

[0051] It should be noted that the type of the power supply 1 in the present invention is not specifically limited, including wind power, photovoltaic power generation or grid power. The power supply 1 is equipped with a voltmeter 2 and an ammeter 3 to determine the change in the power of the electrolyzer; the feedforward controller, the main controller and the sub-controller are not shown in Figure 1 shown.

[0052] For the above electrolysis process flow, the present invention proposes a method for controlling the liquid level of electrolytic water hydrogen production, as shown in Figure 2 shown. The control method includes the following steps:

[0053] S1: Obtain the real-time data of the electrolysis system pressure, the electrolyzer power, the lye temperature, the separator liquid level and the separator set liquid level respectively;

[0054] S2: Take the change values of the electrolysis system pressure, the electrolyzer power, and the lye temperature as the inputs of the corresponding feedforward controllers respectively, and determine the first result according to the output results of the corresponding feedforward controllers;

[0055] S3: Take the real-time data of the separator liquid level and the separator set liquid level as the inputs of the main controller and output the second result;

[0056] S4: Add the first result and the second result as the set value of the sub-controller, take the separator water replenishment flow rate as the feedback value of the sub-controller, take the set value and the feedback value of the sub-controller as the inputs of the sub-controller, and control the water replenishment flow rate according to the output signal of the sub-controller, thereby controlling the separator liquid level.

[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 the oxygen-side separator 11, and the separator liquid level is the actual liquid level of the oxygen-side separator 11; when controlling the liquid level of the hydrogen-side separator, the electrolysis system pressure is the hydrogen-side pressure of the hydrogen-side separator 6, and the separator liquid level is the actual liquid level of the hydrogen-side separator 6. The lye temperature is measured by the temperature collected by the temperature transmitter 5 installed on the oxygen outlet pipeline of the electrolytic cell 4 whether controlling the liquid level of the oxygen-side separator or the hydrogen-side separator; the electrolytic cell power is calculated according to the real-time voltage and current of the 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, taking the change value of the electrolysis system pressure, the change value of the electrolytic cell power, and the change value of the lye temperature as the inputs of the corresponding feedforward controllers respectively, and determining the first result according to the output results of the corresponding feedforward controllers includes the following steps:

[0059] Input the difference between the real-time data of the electrolysis system pressure for two adjacent times into the pressure feedforward controller to output the first information;

[0060] Input the difference between the real-time data of the electrolytic cell power for two adjacent times into the power feedforward controller to output the second information;

[0061] Input the difference between the real-time data of the lye temperature for two adjacent times into the temperature feedforward controller to output the third information;

[0062] Sum up the first information, the second information, and the third information to obtain the first result.

[0063] The following combines Figure 3The control block diagram shown exemplarily illustrates a method for controlling the liquid level of the oxygen-side separator in the process of hydrogen production by electrolyzing water. In this control process, the liquid level L of the oxygen-side separator is used as the main variable, and the water replenishment flow rate F of the oxygen-side separator 11 is used as the secondary variable to form a cascade control system. The liquid level of the oxygen-side separator and the set liquid level x1 of the oxygen-side separator are used as the inputs of the main controller, and the output result of the main controller is x2. At the same time, the change values (disturbance quantities) of the electrolysis system pressure, the electrolysis cell power, and the lye temperature are used as feedforward signals and respectively input into the feedforward controller. After summing their respective output results to obtain x3, it forms an oxygen-side feedforward-cascade control system together with the cascade control system. The sum of the output result x2 of the main controller and the output result x3 of the feedforward controller is used as the set value of the secondary controller, and the water replenishment flow rate F is used as the feedback value of the secondary controller. The set value of the secondary controller and the feedback value of the secondary controller are jointly used as the inputs of the secondary controller. According to the output signal y1 of the secondary controller, it acts on the oxygen-side water replenishment valve 16 to control the water replenishment flow rate, thereby realizing the liquid level control of the oxygen-side separator.

[0064] In the above process, the main controller adopts the PID control algorithm to achieve precise control of the liquid level of the oxygen-side separator, and stabilizes the liquid level of the oxygen-side separator above the set liquid level x1 of the oxygen-side separator. The set liquid level x1 of the oxygen-side separator can be set in the DCS / PLC controller. The liquid level is collected by the oxygen-side liquid level transmitter 12. By comprehensively combining the three control actions of proportional (P), integral (I), and derivative (D), in the proportional part, according to the magnitude of the error signal between the set liquid level x1 of the oxygen-side separator and the liquid level of the oxygen-side separator, the output result x2 is output to reduce the error; in the integral part, by integrating the error signal, the steady-state error is eliminated so that the liquid level of the oxygen-side separator can be stabilized at the set liquid level x1 of the oxygen-side separator; in the derivative part, by differentiating the error signal, the change trend of the error is predicted, and the output result x2 is adjusted in advance, thereby adjusting the liquid level of the oxygen-side separator to ensure a high control quality of the system.

[0065] The secondary controller adopts the P control algorithm to quickly overcome the influence brought by the fluctuation of the water replenishment flow rate. The sum of the output result x2 of the main controller and the output result x3 of the feedforward controller is used as the set value of the secondary controller, and the water replenishment flow rate F of the oxygen-side separator is used as the feedback value of the secondary controller. The set value of the secondary controller and the feedback value of the secondary controller are jointly used as the inputs of the secondary controller. The output y1 of the secondary controller acts on the oxygen-side water replenishment valve 16 to control the water replenishment flow rate of the oxygen-side separator. The existence of the feedback value of the secondary controller reduces the accuracy requirement for the feedforward control model and improves the anti-disturbance ability of the system, with a certain self-adaptive ability.

[0066] The feedforward controller generally adopts static feedforward. For example, a P controller is used as the feedforward controller, and parameter tuning is completed during actual debugging, which can detect changes in system pressure, electrolyzer power, and lye temperature in advance, thereby improving the control quality. In an embodiment of the present invention, the feedforward controller includes a pressure feedforward controller, a power feedforward controller, and a temperature feedforward controller, and the output values of the pressure feedforward controller, the power feedforward controller, and the temperature feedforward controller are summed to obtain x3. In other embodiments of the present invention, the feedforward controller can also adopt dynamic feedforward, and the specific model needs to be determined according to the actual situation on site (the dynamic characteristics of the process interference channel and the control channel). However, its structure is often relatively complex, and it highly depends on the accuracy of the model parameters, requiring a dedicated controller or even a computer to implement, which increases the cost of the electrolysis system.

[0067] For the control of the hydrogen-side liquid level in the electrolytic water hydrogen production process, a PID control algorithm with the oxygen-side separator liquid level as the set value and the hydrogen-side separator liquid level as the actual value can be adopted; a cascade control with the hydrogen-side separator liquid level as the main variable and the hydrogen-side water replenishment flow rate as the secondary variable can also be adopted. In an exemplary embodiment of the present invention, the same feedforward-cascade control method as that for the oxygen-side liquid level control is adopted, and the electrolysis system pressure is replaced with the hydrogen-side pressure of the hydrogen-side separator 6. During this control process, the hydrogen-side liquid level L of the hydrogen-side separator is used as the main variable, and the water replenishment flow rate F of the hydrogen-side separator 6 is used as the secondary variable to form a hydrogen-side feedforward-cascade control (as Figure 4 shown). The hydrogen-side separator liquid level and the set liquid level x1 of the hydrogen-side separator 6 are used as the inputs of the main controller, and the output result of the main controller is x2. At the same time, the change values of the electrolysis system pressure (the hydrogen-oxygen side pressure of the hydrogen-side separator 6), the electrolyzer power, and the lye temperature are used as feedforward signals and are respectively input into the feedforward controller. After summing their respective output results, x3 is obtained, and then a feedforward-cascade control system is formed together with the cascade control system. The output result x2 of the main controller and the output result x3 of the feedforward controller are added together as the set value of the secondary controller, and the water replenishment flow rate F is used as the feedback value of the secondary controller. The set value of the secondary controller and the feedback value of the secondary controller are jointly used as the inputs of the secondary controller, and according to the output signal y1 of the secondary controller, it acts on the hydrogen-side water replenishment valve 10 to control the water replenishment flow rate, thereby realizing the liquid level control of the hydrogen-side separator.

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

[0069] Another exemplary embodiment of the present invention provides an electronic device. As Figure 5As shown, 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] The memory 503 stores a computer program;

[0071] The processor 501 is configured to implement the method for controlling the liquid level of the separator in the electrolytic water hydrogen production process when executing the program stored in the memory 503.

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

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

[0074] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements 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 of a separator in a process of producing hydrogen by electrolysis of water, characterized in that: The control method comprises the following steps: respectively obtain the real-time data of electrolysis system pressure, electrolysis cell power, alkali solution temperature, separator liquid level and separator set liquid level; Using the change value of the electrolysis system pressure, the change value of the electrolytic cell power, and the change value of the alkali solution temperature as inputs of corresponding feedforward controllers, and determining a first result according to the output results of the corresponding feedforward controllers; The real-time data of the separator liquid level and the separator set liquid level are used as inputs of the main controller, and a second result is output; The first result and the second result are added together as the setting value of the sub-controller, the separator water replenishment flow rate is used as the feedback value of the sub-controller, the setting value of the sub-controller and the feedback value of the sub-controller are used together as the input of the sub-controller, and the water replenishment flow rate is controlled according to the output signal of the sub-controller, thereby controlling the separator liquid level; the feedforward controller and the sub-controller adopt the P control algorithm, and the main controller adopts the PID control algorithm.

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

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

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

5. The method for controlling the liquid level of a separator in a process of producing hydrogen by electrolysis of water according to claim 1, characterized in that: Using the change value of the electrolysis system pressure, the change value of the electrolytic cell power, and the change value of the alkali solution temperature as the input of the corresponding feedforward controller, and determining the first result according to the output result of the corresponding feedforward controller includes: Inputting the difference between two adjacent real-time pressure data of the electrolysis system into the pressure feedforward controller, and outputting first information; Inputting the difference between two adjacent electrolytic cell power real-time data into the power feedforward controller, and outputting the second information; The difference between two adjacent alkali solution temperature real-time data is input into the temperature feedforward controller, and the third information is output; The first information, the second information and the third information are summed to obtain a first result.

6. A control system for the liquid level of a separator in the process of producing hydrogen by electrolysis of water, characterized in that: include: An acquisition unit, used to respectively acquire real-time data of electrolysis system pressure, electrolytic cell power, alkali solution temperature, separator liquid level and separator set liquid level; A first result output unit, used to use the change value of the electrolysis system pressure, the change value of the electrolytic cell power, and the change value of the alkali solution temperature as inputs of corresponding feedforward controllers, and determine a first result according to the output results of the corresponding feedforward controllers; A second result output unit, used to use the real-time data of the separator liquid level and the separator set liquid level as inputs of the main controller and output a second result; A liquid level control unit is used to add the first result and the second result as the set value of the sub-controller, and the separator water replenishment flow rate as the feedback value of the sub-controller, and use the set value of the sub-controller and the feedback value of the sub-controller as the input of the sub-controller, and control the water replenishment flow rate according to the output signal of the sub-controller, thereby controlling the separator liquid level; the feedforward controller and the sub-controller adopt the P control algorithm, and the main controller adopts the PID control algorithm.

7. An electrolyzer hydrogen production system, characterized in that: The hydrogen production system includes the control system for the separator liquid level in the process of producing hydrogen by electrolysis of water as described in claim 6.

8. 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 via the communication bus; a memory storing a computer program; The processor is used to implement 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 to 6 when executing the program stored in the memory.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed, the method for controlling the liquid level of a separator in a process of producing hydrogen by electrolysis of water as described in any one of claims 1 to 6 is executed.

Images