Hydrogen production system and cell pressure adjustment method

Abstract

The application discloses a hydrogen production system and an electrolytic cell pressing force adjusting method, and belongs to the technical field of electrolytic hydrogen production equipment control, wherein the hydrogen production system comprises an electrolytic cell and a pressing force adjusting device; the electrolytic cell comprises two oppositely arranged pressing end plates and electrolytic unit groups stacked between the two pressing end plates; at least one end plate is provided with a sensor array outside; the pressing force adjusting device comprises a controller and multiple groups of independent executing mechanisms, and the executing mechanisms correspondingly act on each partition of the end plate. Through a partition distributed sensing architecture, the application combines a pressure mapping and a temperature compensation model to obtain real pressing force of a region, constructs a double-coupling decoupling mechanism based on regional spatial distance and real-time temperature difference to correct pressure deviation, drives the independent partition control of the executing mechanism, realizes high-precision closed-loop control of the pressing force of the end plate, solves the problems of high-temperature measurement distortion and stress coupling of rigid end plates, improves sealing reliability and long-term stability of the pressing force, prolongs the pressure maintaining period and reduces operation and maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology, and in particular to a hydrogen production system and a method for adjusting the clamping force of an electrolyzer. Background Technology

[0002] During the operation of an electrolytic hydrogen production system, the uniformity and stability of the end plate clamping force directly determine the airtightness and operational safety of the electrolyzer. Existing technologies have the following drawbacks: 1) Most existing hydrogen production systems adopt an integral clamping structure, monitoring the clamping force only through a few single-point sensors. This fails to provide feedback on the true stress distribution across the entire end plate, making it difficult to achieve precise, zoned clamping control; 2) Furthermore, the operating temperature of the electrolyzer typically reaches 70℃~120℃, causing strain sensor signals to drift due to temperature fluctuations, resulting in distorted pressure measurements and hindering reliable data for precise control; 3) Simultaneously, the end plate is a continuous rigid body, and adjustments to the local clamping force can trigger stress changes in neighboring areas. Conventional control methods cannot counteract spatial coupling interference or adapt to the thermal stress coupling effects of temperature gradients. This makes it impossible to implement a gradient clamping strategy prioritizing edge sealing, and it is also difficult to maintain a stable sealing clamping force over a long period, leading to the risk of media leakage and gas cross-contamination, thus restricting the system's operational reliability and maintenance cycle.

[0003] Therefore, how to provide a hydrogen production system and electrolyzer clamping force adjustment method with good airtightness and safe operation has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To address at least one of the aforementioned problems, a first embodiment of the present invention provides a hydrogen production system, including an electrolyzer and a clamping force regulating device, wherein... The electrolytic cell includes two clamping end plates arranged opposite each other, and an electrolytic unit group stacked between the two clamping end plates. At least one of the clamping end plates has a sensor array on its surface away from the electrolytic unit group. The sensor array includes multiple sensor groups. The clamping force adjustment device includes a controller and multiple independently controlled actuators. The actuators act on the clamping end plate equipped with a sensor array. The controller is configured to divide the clamping end plate into multiple control areas, each control area corresponding to at least one sensor group and at least one actuator. The sensor group in each control area receives the sensing signals and obtains the actual clamping force received in the control area according to the preset pressure mapping model and temperature compensation model. Based on the spatial geometric distance between each control zone and the real-time temperature difference between each control zone, the pressure difference between the actual clamping force and the preset target pressure value of each control zone is decoupled and weighted to obtain the corrected pressure control value of each control zone. Based on the pressure control value of each control zone, corresponding control commands are generated, and the corresponding actuators are driven to independently adjust the clamping force of the corresponding control zone according to the control commands.

[0005] Optionally, the sensor group includes: A strain sensing unit is used to collect the strain deformation signal of the control area corresponding to the clamping end plate, and the controller is configured to obtain the sensed clamping force received by the clamping end plate based on the strain deformation signal. The temperature sensing unit is used to collect the real-time temperature signal of the control area corresponding to the clamping end plate.

[0006] Optionally, the electrolytic cell further includes a plurality of pressure sensors disposed on the surface of the clamping end plate near the electrolytic unit group. Each control area corresponds to at least one pressure sensor. The pressure sensors are used to collect in-situ measured pressure values ​​of the control area to calibrate the pressure mapping model.

[0007] The present invention also provides a method for adjusting the clamping force of an electrolyzer in the hydrogen production system described above, comprising: The clamping end plate is divided into multiple control areas, each control area corresponding to at least one sensor group and at least one of the aforementioned actuators; The sensor group in each control area receives the sensing signals and obtains the actual clamping force received in the control area according to the preset pressure mapping model and temperature compensation model. Based on the spatial geometric distance between each control zone and the real-time temperature difference between each control zone, the pressure difference between the actual clamping force and the preset target pressure value of each control zone is decoupled and weighted to obtain the corrected pressure control value of each control zone. Based on the pressure control value of each control zone, corresponding control commands are generated, and the corresponding actuators are driven to independently adjust the clamping force of the corresponding control zone according to the control commands.

[0008] Optionally, the sensor group includes a strain sensing unit and a temperature sensing unit, and obtaining the actual clamping force received by the control area according to a preset pressure mapping model and temperature compensation model further includes: According to the pre-set pressure mapping model, the strain deformation signal collected by the strain sensing unit is mapped into the sensing clamping force. The pressure mapping model adopts a third-order polynomial mapping relationship, takes the strain deformation signal as input, takes the pre-calibrated polynomial mapping regression coefficient as parameters, and outputs the sensing clamping force at the corresponding coordinate position by weighted summation of constant term, first strain term, second strain term and third strain term. According to the preset temperature compensation model, the real-time temperature signal collected by the temperature sensing unit is used to correct the temperature drift of the sensed clamping force to obtain the actual clamping force. The temperature compensation model takes the difference between the real-time temperature and the temperature reference point as input, calculates the temperature drift deviation correction factor through a third-order polynomial, and then makes a proportional correction to the sensed clamping force based on the temperature drift deviation correction factor to output the actual clamping force at the corresponding coordinate position.

[0009] Optionally, the step of decoupling and weighting the pressure difference between the actual clamping force and the preset target pressure value of each control area based on the spatial geometric distance between each control area and the real-time temperature difference of each control area, and obtaining the corrected pressure control value of each control area, further includes: The average clamping force difference between each control area is calculated based on the actual clamping force at each coordinate point in each control area and the target pressure value preset in the control area. The spatial and thermal field coupling coefficient is calculated based on the spatial geometric distance between each control area and the real-time temperature difference between each control area. The pressure control value of each control area is obtained based on the average clamping force difference of each control area and the spatial and thermal field coupling coefficient.

[0010] Optionally, the step of calculating the average clamping force difference of each control area based on the actual clamping force at each coordinate point in each control area and the preset target pressure value of the control area further includes: The difference between the target pressure value and the actual clamping force at each coordinate point within each control area is taken as the pressure difference at that coordinate point. The average clamping force difference of the control area is obtained by integrating the pressure difference of all coordinate points within the control area and then dividing it by the area of ​​the control area. The spatial and thermal field coupling coefficient is used to characterize the degree of stress linkage influence between adjacent control areas. It is obtained by weighted summation of mechanical stiffness coupling term and thermal stress coupling term. Among them, the mechanical stiffness coupling term is inversely proportional to the spatial geometric distance between the center points of the two control areas, and is normalized based on the average physical distance between the center points of all adjacent areas, and multiplied by the preset mechanical stiffness coupling weight. The thermal stress coupling term is directly proportional to the real-time temperature difference between the two control areas, and is normalized based on the difference between the highest and lowest temperatures in the entire pressing end plate, and multiplied by the preset thermal stress coupling weight. The pressure control value is based on the average clamping force difference of the corresponding control area, plus the coupling correction amount between the control area and all adjacent control areas; the coupling correction amount is the product of the coupling coefficient of the corresponding adjacent area and the difference between the average clamping force difference of the two areas.

[0011] Optionally, when the control strategy is proportional-integral-derivative (PID) control, the step of generating corresponding control commands based on the pressure control values ​​of each control region further includes: taking the pressure control value as input, calculating the proportional term, integral term, and derivative term respectively, and then summing them to obtain the control command; wherein the proportional term is the product of the pressure control value and a preset proportional coefficient, the integral term is the product of the integral of the pressure control value with respect to time and a preset integral coefficient, and the derivative term is the product of the derivative of the pressure control value with respect to time and a preset derivative coefficient; Optionally, when the control strategy is sliding mode variable structure control, the step of generating corresponding control commands based on the pressure control values ​​of each control region further includes: constructing a sliding surface function, wherein the sliding surface function is composed of a linear combination of the pressure control value and the derivative of the pressure control value with respect to time, wherein the pressure control value corresponds to a preset sliding surface slope coefficient; and generating corresponding control commands based on the sliding surface function and the set sub-control strategy.

[0012] Optionally, before generating corresponding control commands based on the pressure control values ​​of each control zone, the electrolyzer clamping force adjustment method further includes: calculating a creep relaxation compensation command based on the pressure holding time when the hydrogen production system is in a pressure holding state, according to a pre-set creep relaxation feedforward compensation unit; the creep relaxation compensation command follows an exponential change law, gradually approaching the maximum creep compensation amplitude allowed by the system as the pressure holding time increases, and the rate of change is determined by a pre-set creep decay time constant of the clamping end plate structure; The step of generating corresponding control commands based on the pressure control values ​​of each control zone further includes: superimposing the creep relaxation compensation command into the control command.

[0013] Optionally, before driving the corresponding actuators to independently adjust the clamping force of the corresponding control areas according to the control command, the electrolytic cell clamping force adjustment method further includes: The control command after the superimposed creep relaxation compensation command is clamped according to the preset safety limiting unit, and the control command is constrained between the preset soft protection lower limit command and the soft protection upper limit command to obtain the final control command; the soft protection lower limit command and the soft protection upper limit command are both lower than the corresponding pressure hard threshold of the system.

[0014] This invention addresses existing problems by developing a method for adjusting the clamping force of a hydrogen production system and an electrolyzer. It involves partitioning the end plate and forming a distributed control architecture with corresponding sensor arrays and independent actuators for each partition. During operation, the sensor groups in each region first collect sensing signals. These signals are then processed using a preset pressure mapping and temperature compensation model to eliminate temperature drift interference, obtaining the true clamping force for each region and ensuring the accuracy of measurement data under high-temperature conditions. Furthermore, a dual-coupling and decoupling mechanism is constructed by combining the spatial geometric distance between regions with the real-time temperature difference. This mechanism actively counteracts the neighboring stress linkage effect and thermal stress interference of the rigid end plate when calculating pressure deviations, avoiding global stress fluctuations caused by local adjustments. Finally, the independent actuators in each partition output corresponding control commands to achieve closed-loop precise control of the end plate clamping force. This embodiment, through the synergistic effect of various components in the hydrogen production system, can form an edge-priority gradient clamping force field to improve sealing reliability and maintain stable clamping force over a long period, effectively extending the pressure holding period, reducing leakage risk and maintenance costs, thus overcoming the problems existing in the prior art and showing broad application prospects. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the structure of a hydrogen production system according to an embodiment of the present invention is shown; Figure 2 A schematic diagram of the hydrogen production system according to another embodiment of the present invention is shown; Figure 3 This diagram illustrates the structure of a hydrogen production system according to yet another embodiment of the present invention. Figure 4 This diagram illustrates the structure of the surface of the clamping end plate away from the electrolysis unit group according to an embodiment of the present invention. Figure 5 This diagram illustrates the structure of the surface of the clamping end plate away from the electrolysis unit group according to another embodiment of the present invention. Figure 6This diagram illustrates the structure of the surface of the clamping end plate away from the electrolysis unit group according to another embodiment of the present invention; Figure 7 This diagram illustrates the structure of the pressing end plate near the electrolysis unit assembly according to an embodiment of the present invention. Figure 8 This diagram illustrates the structure of the pressing end plate near the electrolysis unit assembly according to another embodiment of the present invention. Figure 9 This diagram illustrates the structure of the surface of the clamping end plate near the electrolysis unit assembly according to another embodiment of the present invention. Figure 10 A flowchart of an embodiment of the electrolytic cell clamping force adjustment method of the present invention is shown; Figure 11 A schematic diagram of the structure of a computer device according to another embodiment of the present invention is shown. Detailed Implementation

[0017] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention. Based on the above problems and the causes of these problems, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, one embodiment of the present invention provides a hydrogen production system 100, including an electrolyzer 10 and a clamping force adjustment device.

[0018] The electrolytic cell 10 includes two clamping end plates 11 arranged opposite to each other, and an electrolytic unit group 12 stacked between the two clamping end plates 11. At least one of the clamping end plates 11 has a sensor array on the side surface away from the electrolytic unit group 12. The sensor array includes multiple sensor groups 13. The clamping force adjustment device includes a controller and multiple independently controlled actuators 22. The actuators 22 act on the clamping end plate 11 equipped with a sensor array. The controller is configured to: The clamping end plate is divided into multiple control areas, each control area corresponding to at least one sensor group and at least one of the actuators; The sensor group in each control area receives the sensing signals and obtains the actual clamping force received in the control area according to the preset pressure mapping model and temperature compensation model. Based on the spatial geometric distance between each control zone and the real-time temperature difference between each control zone, the pressure difference between the actual clamping force and the preset target pressure value of each control zone is decoupled and weighted to obtain the corrected pressure control value of each control zone. Based on the pressure control value of each control zone, corresponding control commands are generated, and the corresponding actuators are driven to independently adjust the clamping force of the corresponding control zone according to the control commands.

[0019] In this embodiment, Figure 1 , Figure 2 , Figure 3 The diagram illustrates the structure of the hydrogen production system, which includes an electrolyzer 10 and a pressure regulating device. The electrolyzer 10 comprises two opposing pressure end plates 11 and an electrolysis unit group 12 stacked between the two pressure end plates 11. In practical industrial applications, the electrolysis unit group 12 can be composed of dozens to hundreds of electrolysis cells stacked in series. Each electrolysis cell sequentially includes an anode plate, an anode electrode, a diaphragm, a cathode electrode, and a cathode plate. Adjacent cells are separated by bipolar plates to facilitate fluid and current conduction. The pressure regulating scheme of this embodiment is compatible with various technologies such as alkaline electrolyzers (ALK), proton exchange membrane electrolyzers (PEM), and anion exchange membrane electrolyzers (AEM). It is also suitable for electrolyzer structures with both square and circular end plates, requiring no fundamental modifications for different cell types, thus having a wide range of applications.

[0020] The clamping end plate 11, serving as the pressure-bearing and fastening base of the fuel cell stack, is typically made of high-strength carbon steel, stainless steel, or aluminum alloy, possessing sufficient cross-sectional rigidity to ensure uniform transmission of clamping force. In traditional electrolytic cell overall clamping schemes, the clamping end plate applies pressure only through a few bolts / hydraulic cylinders at the center or corners, easily leading to insufficient edge clamping force and central stress concentration, resulting in uneven compression of the sealing gasket and safety risks such as alkali leakage and hydrogen-oxygen gas mixing. This embodiment divides the clamping end plate into sections, forming a distributed control architecture with sensor arrays corresponding to each section and independent actuators. Specifically, at least one clamping end plate 11 has a sensor array on its surface away from the electrolysis unit group 12. The sensor array includes multiple sensor groups 13 arranged in a matrix or ring array, covering the entire effective pressure-bearing area of ​​the end plate. In this embodiment, the sensor array can be placed only on the outer side of the movable clamping end plate, or it can be evenly placed on the outer sides of both clamping end plates to achieve synchronous monitoring and bidirectional control of the clamping force on both sides.

[0021] In this embodiment, the clamping force adjustment device includes a controller and multiple independently controlled actuators 22. The actuators 22 act on the clamping end plate 11 equipped with a sensor array. The number of actuators 22 in this embodiment corresponds one-to-one with the control area. For example, various types such as hydraulic drive, electric servo, or pneumatic can be used, which can be flexibly selected according to the tonnage of the electrolytic cell and the working conditions. Specifically, for large-tonnage industrial electrolyzers with a single-cell hydrogen production capacity exceeding 1000 Nm³ / h, multiple independent servo hydraulic cylinders can be used as actuators. These cylinders are evenly distributed along the end plate's partitions, with the cylinder body fixed to the outer support frame. The piston rod end abuts against the corresponding partition of the clamping end plate via a ball joint structure. Precise adjustment of the clamping force is achieved by regulating the hydraulic cylinder's oil supply pressure, resulting in high output force and stable operation. For smaller to medium-tonnage electrolyzers or scenarios requiring high response speed, a servo motor-driven ball screw mechanism can be used as the actuator. Fine-tuning of the clamping force is achieved through precise motor rotation control, resulting in faster response and higher control accuracy. Each actuator is equipped with an independent drive unit, capable of receiving controller commands for pressurization or depressurization without interference, thus enabling independent control of the clamping force in each partition. Compared to traditional single-cylinder or diagonally double-cylinder overall clamping methods, multi-partition independent actuators can flexibly adjust the clamping force distribution in different areas of the end plate, better matching the pressure requirements of the sealing surface.

[0022] The controller is communicatively connected to the sensor array and each group of actuators 22, serving as the control core of the entire hydrogen production system. Its hardware can take various forms, such as a programmable logic controller (PLC), an industrial control computer, or an embedded ARM control board. The controller integrates functional units such as a data acquisition module, a calibration calculation module, a decoupling control module, an instruction output module, and a safety protection module, and is configured to execute specific control logic. Specifically, the process includes: **Regional Division:** The clamping end plate is pre-divided into multiple control zones according to specific requirements. Each control zone corresponds to at least one sensor group and at least one actuator. **Real Pressure Calculation:** Sensing signals collected by the sensor groups in each control zone are received. The actual clamping force received by the control zone is obtained based on a pre-set pressure mapping model and temperature compensation model. **Dual Coupling Decoupling Correction:** Based on the spatial geometric distance between each control zone and the real-time temperature difference between each control zone, the pressure difference between the actual clamping force of each control zone and the pre-set target pressure value is decoupled and weighted to obtain the corrected pressure control value for each control zone. **Partitioned Closed-Loop Execution:** Corresponding control commands are generated based on the pressure control values ​​of each control zone. The corresponding actuators are then driven to independently adjust the clamping force of their respective control zones according to these control commands.

[0023] In this embodiment, pressure mapping and temperature compensation solve the problem of measurement distortion at high temperatures, providing reliable basic data for closed-loop control; dual-coupling decoupling correction solves the problem of stress linkage in the rigid end plate area, avoiding the difficulty of adjustment affecting the surrounding area in zone control; and independent zone execution provides the hardware foundation for precise control. These three components work together and are indispensable: without accurate measurement data, decoupling control loses reliable input; without decoupling correction, zone execution will exacerbate stress distribution disorder; and without zone execution mechanisms, even the most precise measurements and calculations cannot be implemented. Through the synergistic effect of each module, the hydrogen production system in this embodiment achieves high-performance indicators such as end plate clamping force calibration accuracy of ±0.5% of full scale, steady-state error of no more than 1%, and response time of no more than 2 seconds, significantly superior to existing technical solutions.

[0024] In actual operation, sensor groups in each region first collect sensing signals. These signals are then processed using a preset pressure mapping and temperature compensation model to eliminate temperature drift interference, yielding the true clamping force for each region and ensuring the accuracy of measurement data under high-temperature conditions. Next, a dual-coupling and decoupling mechanism is constructed by combining the spatial geometric distance between regions with the real-time temperature difference. This mechanism actively counteracts the neighboring stress linkage effect and thermal stress interference of the rigid end plate when calculating pressure deviations, avoiding global stress fluctuations caused by local adjustments. Finally, corresponding control commands are output through independent actuators in each region, achieving closed-loop precise control of the end plate clamping force. This embodiment, through the synergistic effect of various components of the hydrogen production system, can form an edge-priority gradient clamping force field to improve sealing reliability and maintain stable clamping force over a long period, effectively extending the pressure holding period and reducing leakage risk and maintenance costs.

[0025] In an optional embodiment, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 , Figure 5 , Figure 6 As shown, the sensor group 13 includes: The strain sensing unit 132 is used to collect the strain deformation signal of the control area corresponding to the clamping end plate 11. The controller is configured to obtain the sensed clamping force received by the clamping end plate based on the strain deformation signal. Temperature sensing unit 131 is used to collect real-time temperature signals of the control area corresponding to the pressing end plate 11.

[0026] In this embodiment, Figure 4 , Figure 5 , Figure 6 To be respectively with Figure 1 , Figure 2 , Figure 3The corresponding structural diagram of the surface of the clamping end plate away from the electrolysis unit group shows that each sensor group 13 includes a strain sensing unit 132 and a temperature sensing unit 131, which are arranged in conjunction at the same measuring point to realize the synchronous acquisition of strain signals and temperature signals.

[0027] Specifically, in this embodiment, the strain sensing unit 132 is used to collect the strain deformation signal of the control area corresponding to the clamping end plate 11. The controller is configured to obtain the sensed clamping force received by the clamping end plate based on the strain deformation signal. The strain sensing unit 132 in this embodiment can be a resistive strain gauge, a fiber Bragg grating (FBG) strain sensor, or similar type. For the working temperature range of 70℃~120℃ in the electrolytic cell, this embodiment selects a medium-temperature self-compensating strain gauge, which has a certain temperature self-compensation capability through the grating wire material ratio. Combined with the temperature compensation in this embodiment, the measurement accuracy can be further improved. The strain sensing unit 132 in this embodiment is fixed to the outer surface of the clamping end plate by high-strength structural adhesive bonding or spot welding, maintaining synchronous deformation with the clamping end plate, thereby converting the compressive deformation of the clamping end plate into an acquireable electrical or optical signal.

[0028] Specifically, in this embodiment, the temperature sensing unit 131 is used to acquire the real-time temperature signal of the control area corresponding to the clamping end plate 11. The temperature sensing unit 131 in this embodiment can be a surface-mount platinum resistance thermometer (PT100 / PT1000), a K-type thermocouple, or a temperature sensing element integrated inside the strain gauge. Its placement is adjacent to the strain sensing unit 132, for example, with a spacing of less than or equal to 5 mm to ensure that the acquired temperature is the true temperature of the corresponding strain measurement point, providing an accurate temperature data source for temperature drift compensation.

[0029] Compared to traditional solutions where temperature and strain measurement points are separated, making it impossible to accurately correspond to the actual temperature of each strain point and only the overall average temperature can be used for compensation, resulting in insufficient compensation accuracy in areas with large local temperature differences, this embodiment uses a method of deploying strain sensors and temperature sensors at the same point to achieve real-time sensing of each control area on the clamping end plate, ensuring the accuracy of strain deformation and temperature compensation from a hardware perspective.

[0030] In an optional embodiment, such as Figure 1 , Figure 2 , Figure 3 ,as well as Figure 7 , Figure 8 , Figure 9 As shown, the electrolytic cell 10 also includes a plurality of pressure sensors 133 disposed on the surface of the pressing end plate 11 near the electrolytic unit group 12, with each control area corresponding to at least one pressure sensor 133.

[0031] The pressure sensor is used to collect in-situ measured pressure values ​​in the control area to calibrate the pressure mapping model.

[0032] In this embodiment, Figure 7 , Figure 8 , Figure 9 To be respectively with Figure 1 , Figure 2 , Figure 3 A schematic diagram of the structure of the corresponding clamping end plate near the electrolysis unit group is shown. Each control area corresponds to at least one pressure sensor 133. The pressure sensor is used to collect the in-situ measured pressure value of the control area. In this embodiment, the pressure sensor 133 can be a thin-film pressure sensor, a piezoelectric pressure sensor, or a piezoresistive pressure sensor. It is embedded in the inner side of the clamping end plate, for example, in a processing groove on the inner side of the clamping end plate. Its pressure-bearing surface is in direct contact with the end face sealing structure and the electrode frame structure of the fuel cell stack, and can directly measure the actual interface clamping force of the area.

[0033] It is worth noting that the pressure sensor in this embodiment is used during the system initialization and calibration phase. Different levels of clamping force are applied step-by-step by the actuator, while strain signals at corresponding locations and in-situ pressure data from the pressure sensor are collected simultaneously. The coefficients of the pressure mapping model can then be obtained through polynomial fitting. Therefore, during long-term system operation, the in-situ data from the pressure sensor can be periodically used to dynamically calibrate the strain mapping model, offsetting measurement drift caused by sensor aging and structural fatigue, further improving long-term measurement reliability. In other words, this embodiment utilizes the pressure sensor on the inner side of the clamping end plate for calibration while simultaneously using the strain sensor on the outer side for real-time monitoring, effectively balancing measurement accuracy, operational reliability, and equipment cost, thus possessing high engineering application value.

[0034] Based on the hydrogen production system of the above embodiments, one embodiment of the present invention also provides a method for adjusting the clamping force of an electrolyzer, such as... Figure 10 As shown, it includes: The clamping end plate is divided into multiple control areas, each control area corresponding to at least one sensor group and at least one of the aforementioned actuators; The sensor group in each control area receives the sensing signals and obtains the actual clamping force received in the control area according to the preset pressure mapping model and temperature compensation model. Based on the spatial geometric distance between each control zone and the real-time temperature difference between each control zone, the pressure difference between the actual clamping force and the preset target pressure value of each control zone is decoupled and weighted to obtain the corrected pressure control value of each control zone. Based on the pressure control value of each control zone, corresponding control commands are generated, and the corresponding actuators are driven to independently adjust the clamping force of the corresponding control zone according to the control commands.

[0035] In this embodiment, based on the hardware configuration of the hydrogen production system, dynamic and precise control of the electrolyzer end plate clamping force is achieved through a closed-loop control of the entire process, including partitioned sensing, high-precision calibration, dual coupling decoupling, and partitioned execution.

[0036] To further illustrate the specific implementation of this embodiment, taking the hydrogen production process of a time-based hydrogen production system as an example, the adjustment of the electrolyzer clamping force is explained, specifically including the following steps: The first step is to divide the clamping end plate into multiple control areas, each control area corresponding to at least one sensor group and at least one of the aforementioned actuators.

[0037] In this embodiment, the division of the control area is the foundation of the entire distributed control. The partitioning method directly determines the balance between control accuracy and control complexity. For example, the uniform partitioning method and the functional partitioning method can be flexibly selected according to the structure and sealing requirements of the electrolytic cell. Specifically, the uniform partitioning method divides the effective pressure-bearing surface of the pressing end plate into equal areas according to a rectangular grid or annular grid, with each control area having a basically consistent area. For example, for square end plates, 3×3, 4×4, and 5×5 rectangular grids are usually used; for circular end plates, a central circle plus multiple layers of annular sectors are usually used. The uniform partitioning method has the advantages of simple partitioning rules, neat arrangement of sensors and actuators, convenient calculation of coupling coefficients, and strong versatility. It is suitable for small and medium-sized electrolytic cells with symmetrical structures and uniformly distributed sealing surfaces. The functional zoning method divides the electrolytic cell into zones based on the internal functional structure corresponding to the clamping end plate. The clamping end plate is divided into an edge sealing zone, a flow channel corresponding zone, and a central reaction zone. The boundaries of each zone correspond one-to-one with the locations of the sealing grooves, electrode frames, and flow channels in the electrolytic cell. For example, the edge sealing zone corresponds to the installation position of the sealing gaskets around the clamping end plate. This area directly determines the airtightness of the electrolytic cell and is the core area for clamping force control; therefore, it is usually divided into multiple independent sub-zones for precise control. The flow channel corresponding zone corresponds to the flow channel positions of the electrolyte inlet / outlet and gas inlet / outlet. This area has strong fluid scouring and large temperature fluctuations, requiring separate clamping force control to ensure sealing. The central reaction zone corresponds to the core reaction area of ​​the fuel cell stack. This area has a large area and uniform structure, so the clamping force does not need to be too high to avoid excessive compression of the electrodes and diaphragm, which would increase mass transfer resistance and affect electrolysis efficiency. The functional zoning method closely matches the actual functional requirements of the electrolytic cell, ensuring the clamping force of the sealing area while preventing overpressure damage to core components in the reaction area. This achieves a balance between sealing reliability and stack performance, making it suitable for large industrial-grade electrolytic cells.

[0038] It is worth noting that this embodiment is only used to illustrate the specific implementation of this application. This application does not specifically limit the number of partitions, the shape and area of ​​each control area. Those skilled in the art should select an appropriate number of partitions, as well as the shape and area of ​​the control area, according to the actual application requirements, so as to achieve the design principle of partition sensing and independent adjustment of the pressing end plate. This will not be elaborated here.

[0039] The second step is to receive the sensing signals collected by the sensor groups in each control area, and obtain the actual clamping force received in the control area according to the preset pressure mapping model and temperature compensation model.

[0040] In this embodiment, the system collects the sensing signals of the sensor groups in each control area in real time, and obtains the actual clamping force of each control area through two-level calculations of pressure mapping model and temperature compensation model, thereby improving the overall adjustment accuracy based on the actual clamping force of each control area.

[0041] In an optional embodiment, the sensor group includes a strain sensing unit and a temperature sensing unit, and obtaining the actual clamping force received by the control area according to a preset pressure mapping model and temperature compensation model further includes: According to the pre-set pressure mapping model, the strain deformation signal collected by the strain sensing unit is mapped into the sensing clamping force. Specifically, the pressure mapping model adopts a third-order polynomial mapping relationship, takes the strain deformation signal as input, takes the pre-calibrated polynomial mapping regression coefficient as parameters, and outputs the sensing clamping force at the corresponding coordinate position by weighted summation of constant term, first strain term, second strain term and third strain term.

[0042] In mathematical terms, the pressure mapping model is:

[0043] in, The coordinates of the clamping end plate are the spatial coordinates on the plane. Indicates the coordinates located on the clamping end plate Sensing the clamping force at the location, Representing coordinates The strain signal collected by the strain sensing unit at the location, These are the coefficients of the polynomial mapping regression; According to the preset temperature compensation model, the real-time temperature signal collected by the temperature sensing unit is used to correct the temperature drift of the sensed clamping force to obtain the actual clamping force. Specifically, the temperature compensation model takes the difference between the real-time temperature and the temperature reference point as input, calculates the temperature drift deviation correction factor through a third-order polynomial, and then makes a proportional correction to the sensed clamping force based on the temperature drift deviation correction factor to output the actual clamping force at the corresponding coordinate position.

[0044] In mathematical terms, the temperature compensation model is as follows:

[0045] in, Coordinates at time t The actual clamping force at the point. For real-time runtime variables, The temperature drift correction factor is calculated using the following formula:

[0046] in, The real-time temperature signal acquired by the temperature sensing unit. As a temperature reference point, These are the temperature polynomial correction coefficients.

[0047] In this embodiment, firstly, according to the pre-set third-order polynomial strain-pressure mapping model, the strain signal collected by the strain sensing unit is mapped into the sensed clamping force; then, according to the pre-set temperature compensation model, the real-time temperature signal collected by the temperature sensing unit is used to correct the temperature drift, and the final actual clamping force is obtained.

[0048] Specifically, traditional strain-pressure conversion typically uses linear models, such as those containing only constant and first-order terms, assuming a direct proportionality between strain and pressure. However, in actual working conditions, the clamping end plate is a large-size thin-plate structure. As the clamping force increases, the bending deformation of the plate exhibits geometrical nonlinear characteristics, and the compressive stiffness of the sealing gasket also has significant nonlinearity, resulting in a non-strict linear relationship between strain and pressure. If a linear model is used, significant measurement errors will occur in the high-pressure range, typically reaching 3% to 5% at full scale. This embodiment uses a third-order polynomial mapping model, which can accurately fit the strain-pressure nonlinear relationship of the end plate across the entire range from low to high pressure, significantly improving the measurement accuracy across the entire range. Among them, the constant term... Corresponding to the initial zero-point offset under zero load, it cancels the initial unbalanced output of the sensor; primary term The corresponding linear stiffness coefficient characterizes the proportional relationship under small deformations; the quadratic term... With cubic terms Corresponding to the nonlinear deformation correction term, the stiffness variation law under large deformation is fitted.

[0049] It is worth noting that the polynomial coefficients of the pressure mapping model in this embodiment were obtained through in-situ calibration experiments. The specific calibration process includes the following steps: First, after the electrolytic cell is assembled, the actuator applies a progressively increasing standard pressure to the clamping end plate, with pressure levels covering 0 to 120% of the full scale. Each pressure level is held for more than 30 seconds. After the stress stabilizes, the strain value at the corresponding measuring point and the in-situ real pressure value of the inner pressure sensor are collected to obtain multiple sets of calibration data pairs (strain, real pressure).

[0050] Second, the least squares method is used to fit a third-order polynomial to all calibration data, and the normal equations are solved to obtain... Four coefficients.

[0051] Third, the fitted coefficients are written into the controller's non-volatile storage unit as fixed mapping parameters for that measurement point.

[0052] This embodiment uses the above calibration process to ensure that the mapping model of each measuring point is adapted to the structural stiffness characteristics of its location, eliminating individual differences caused by uneven thickness of the clamping end plate, processing tolerances, and installation deviations, and achieving accurate mapping.

[0053] The third-order polynomial temperature drift correction temperature compensation model in this embodiment is based on the obtained original sensing clamping force, and then uses the real-time temperature signal collected by the temperature sensing unit to perform temperature drift correction to obtain the final actual clamping force.

[0054] Considering that the operating temperature of an electrolytic cell is typically between 70℃ and 120℃ during normal operation, far exceeding the room temperature calibration temperature, strain sensors experience temperature changes. Firstly, the resistance of the sensitive grid metal material changes with temperature. Secondly, the difference in thermal expansion coefficients between the sensor substrate and the clamping end plate generates additional spurious strain. Both factors contribute to temperature drift, causing the measured strain value to include a large amount of non-stress-generated heat output, ultimately resulting in severely distorted pressure calculations. Therefore, under experimental conditions of 100℃, the thermal output drift of ordinary strain gauges can lead to pressure measurement errors exceeding 10%, failing to meet high-precision control requirements. Traditional temperature compensation typically uses first-order linear compensation, which can only offset part of the linear thermal drift. For a wide temperature range above 70℃, the proportion of nonlinear thermal drift increases significantly, leaving a 3% to 5% error even after compensation. This embodiment employs a third-order polynomial temperature drift correction model, which can simultaneously offset linear, quadratic, and cubic nonlinear thermal output errors. Within the full operating temperature range of 70℃ to 120℃, the measurement error caused by temperature drift is controlled within 0.5%, achieving high-precision pressure measurement at high temperatures.

[0055] It is worth noting that the temperature correction coefficient of the temperature compensation model in this embodiment was obtained through a high-temperature no-load thermal output experiment. The specific calibration process includes the following steps: First, place the clamped end plate sample with strain sensor and temperature sensor attached into the high and low temperature test chamber. Under free conditions without any load, gradually increase the temperature from room temperature, covering the temperature range of 20℃ to 150℃. Hold each temperature point for more than 60 minutes to make the overall temperature of the sample uniform.

[0056] Second, the output value of the strain sensor is collected at each temperature point. This output value is entirely generated by temperature drift, which is the false strain value at the corresponding temperature.

[0057] Third, the spurious strain values ​​at each temperature point are converted into corresponding spurious pressure values ​​using a pressure mapping model, and the relative error ratio at different temperatures is calculated.

[0058] Fourth, the temperature-relative error data are fitted with a third-order polynomial using the least squares method to obtain the solution. Three temperature correction factors.

[0059] Through the above calibration, each measuring point has temperature compensation parameters adapted to its own sensor characteristics, and the compensation accuracy is much higher than that of general linear compensation schemes.

[0060] The third step involves decoupling and weighting the pressure difference between the actual clamping force and the preset target pressure value in each control area based on the spatial geometric distance between each control area and the real-time temperature difference between each control area, and obtaining the corrected pressure control value for each control area.

[0061] In this embodiment, after obtaining the actual clamping force at each coordinate point, the average actual clamping force of each control area is calculated by area integration, serving as the overall pressure characterization of that area. Specifically, the calculation method involves taking the area-weighted average of the actual pressures at all measuring points within the area, ensuring that the area pressure value accurately reflects the overall clamping state of that area. For discretely deployed sensor measuring points, a trapezoidal numerical integration method can be used to calculate the average area pressure, simplifying the calculation while maintaining accuracy and meeting the response speed requirements of real-time control.

[0062] In an optional embodiment, the average clamping force difference between each control area is calculated based on the actual clamping force at each coordinate point in each control area and the target pressure value preset in the control area. The spatial and thermal field coupling coefficient is calculated based on the spatial geometric distance between each control area and the real-time temperature difference between each control area. The pressure control value of each control area is obtained based on the average clamping force difference of each control area and the spatial and thermal field coupling coefficient.

[0063] In this embodiment, after obtaining the actual clamping force of each control area, the pressure deviation is calculated and decoupling correction is performed, which solves the key problem of mutual interference of regional stress in rigid end plate partition control.

[0064] In an optional embodiment, the step of calculating the average clamping force difference of each control area based on the actual clamping force at each coordinate point in each control area and the preset target pressure value of the control area further includes: The pressure difference between each coordinate point is calculated based on the actual clamping force at each coordinate point in each control area and the preset target pressure value of the control area. The pressure difference between the coordinate points is:

[0065] in, coordinates The pressure difference at the current coordinate point. Preset coordinates The target pressure value of the controlled area. coordinates The actual clamping force; Based on the first pressure difference value of each coordinate point in each control area, calculate the average clamping force difference value of each control area. The average clamping force difference value is:

[0066]

[0067] in, For the first i The average difference in clamping force in the region at the current moment. For the first i The area of ​​the region For the first i The integration region corresponding to the region. ,in, , , , It is the first i The range of coordinate values ​​for the region; The spatial and thermal field coupling coefficient is used to characterize the degree of stress linkage influence between adjacent control areas. It is obtained by weighted summation of mechanical stiffness coupling term and thermal stress coupling term. Among them, the mechanical stiffness coupling term is inversely proportional to the spatial geometric distance between the center points of the two control areas, and is normalized based on the average physical distance between the center points of all adjacent areas, and multiplied by the preset mechanical stiffness coupling weight. The thermal stress coupling term is directly proportional to the real-time temperature difference between the two control areas, and is normalized based on the difference between the highest and lowest temperatures in the entire pressing end plate, and multiplied by the preset thermal stress coupling weight. Specifically, in mathematical expression, the coupling coefficient between the space and the thermal field is:

[0068] in, For the first Region and the Coupling influence coefficient between regions, the first i The coordinates of the center point of each region are ( x i ,y i ), No. j The coordinates of the center point of each region are ( x j , y j ), i and j All are integers ≥ 1. i ≠ j ; For mechanical stiffness coupling weights, For the first Region and the Spatial geometric distance of the region center The average physical distance between the center points of all adjacent regions is:

[0069] Among them, the region i The coordinates of the center point are ( x i , y i ),area j The coordinates of the center point are ( x j , y j ), i , j All are integers ≥ 1, M is the total number of pairs of adjacent regions, and d ij Adjacent areas i , j Euclidean distance between the center points The thermal stress coupling weights are for two adjacent control regions. For the first The current real-time temperature of the area For the first The current real-time temperature of the area; This refers to the highest temperature in each control zone of the clamping end plate. This refers to the lowest temperature in each control zone of the clamping end plate; The pressure control value is:

[0070] in, for t Time control area i Pressure control value.

[0071] In this embodiment, the specific steps include: First, calculate the initial pressure deviation. Based on the target pressure value and actual clamping force of each control zone, calculate the initial average clamping force difference for each zone. The target pressure value is the system-preset target clamping force for each control zone, set as a gradient distribution according to the sealing requirements of the specific hydrogen production system. For example, the target pressure in the edge sealing zone is higher than that in the central reaction zone, achieving a gradient sealing strategy between the edge and center positions. When the value is positive, it indicates that the actual pressure at that point is lower than the target pressure, and the actuator needs to increase the pressure; when... A negative value indicates that the actual pressure at that point is higher than the target pressure, requiring the actuator to release pressure. Based on this, the average pressure difference for each control area is calculated. For discretely deployed sensor measuring points, the average difference for the area can be calculated using numerical integration, i.e., taking the arithmetic mean or area-weighted average of the pressure differences at all measuring points within the area. This simplifies the calculation and meets the response speed requirements of real-time control.

[0072] Second, the spatial and thermal coupling coefficients are calculated. The clamping end plate is a continuous rigid structure. When a clamping force is applied to a certain area, the bending deformation of the clamping end plate will cause the clamping force in adjacent areas to change accordingly, i.e., there is a mechanical stiffness coupling effect. At the same time, the temperature difference between different areas will produce thermal expansion and contraction differences, triggering additional thermal stress, which will further change the stress distribution between areas, i.e., the thermal stress coupling effect. The combined effect of these two coupling effects greatly reduces the effectiveness of traditional independent zone control, and may even lead to increasingly chaotic and oscillating situations. This embodiment constructs a spatial and thermal field dual coupling influence coefficient matrix that includes both spatial geometric distance and regional temperature difference, quantitatively characterizing the degree of mutual influence between adjacent areas. Among them, the mechanical stiffness coupling weight... This parameter characterizes the degree of mutual entanglement between the clamping end plates as continuous rigid bodies under physical stress. It can be obtained through finite element simulation or actual pressure testing. The smaller the stiffness and the thinner the thickness of the clamping end plates, the better. The larger the value, the greater the mutual influence between the two regions under stress; the greater the distance, the smaller the mutual influence. This embodiment uses the reciprocal of the distance to characterize the coupling strength. The thermal stress coupling weight between two adjacent control regions... This parameter characterizes the degree to which thermal expansion and contraction between two control regions cause additional tension in their respective stress fields due to the temperature difference. This parameter can be obtained through thermo-structural coupled finite element simulation or temperature difference experiments. The greater the temperature difference between the two control regions, the greater the difference in thermal expansion, and the stronger the resulting additional thermal stress coupling effect. When the temperature difference is zero, the thermal stress coupling weight... It is zero.

[0073] The coupling coefficient in this embodiment considers the coupling effects of both mechanical stiffness and thermal stress, which is more in line with the actual operating conditions of the electrolytic cell compared to the single-dimensional decoupling scheme in the prior art that only considers spatial distance. For example, during the operation of the electrolytic cell, due to the uneven distribution of electrolyte inlet and outlet and current density, there will be obvious temperature gradients in different areas of the clamping end plate. For example, the temperature of the edge area is low and the temperature of the center area is high, with a temperature difference of up to 10℃~30℃. The thermal stress generated by this temperature gradient will significantly change the stress distribution of the clamping end plate. If it is not compensated, it will cause the clamping force in the sealing area to deviate from the target value and cause leakage risk. Therefore, this embodiment constructs a dual coupling coefficient to quantitatively describe the degree of mutual influence between any two adjacent areas.

[0074] Third, the corrected pressure control value is calculated. Based on the regional average pressure difference and the coupling influence coefficient, the original deviation is decoupled and weighted to obtain the corrected pressure control value for each region.

[0075] Specifically, in the formula Indicates the first i Control area and the first j The deviation difference of the control area, when i Control area deviation greater than j When the control area is in use, a positive difference indicates that... i The control area requires more pressurization; due to the regional coupling effect, the... i Pressurization of the control area will drive j The pressure in the control area is rising, therefore it is necessary to... i A coupling correction term is superimposed on the original deviation of the control area to offset the effects of linkage in advance. Specifically, if only the original deviation is considered... control i The actuator in the control area is pressurized, and after pressurization, not only i Pressure rises in the controlled area, and in adjacent areas... j The pressure in the controlled area will also passively increase, leading to j Overpressure occurs in the control region; however, through the coupling correction term, in the calculation... i When controlling the control range, the impact on the control range should be considered in advance. j The linkage effect of the control area is corrected simultaneously. jThe control deviation in the control area is ultimately adjusted synchronously across all areas, bringing them closer to the target value, thus avoiding repeated oscillations caused by individual adjustments. This embodiment, through this neighborhood decoupling weighted correction method, effectively suppresses stress linkage interference from the rigid clamping end plate, transforming independent control into collaborative regulation, and significantly improving the uniformity and stability of the clamping force distribution.

[0076] The fourth step is to generate corresponding control commands based on the pressure control values ​​of each control zone, and drive the corresponding actuators to independently adjust the clamping force of the corresponding control zone according to the control commands.

[0077] In this embodiment, after obtaining the corrected pressure control value, the controller generates control commands for the corresponding actuator according to the preset control algorithm and drives the actuator to adjust the clamping force of the corresponding control area, and returns to the second step to continuously collect data to form a complete closed-loop control.

[0078] In an optional embodiment, when the control strategy is proportional-integral-derivative control, the step of generating corresponding control commands based on the pressure control values ​​of each control region further includes:

[0079] in, The control command. , , These are the preset proportional, integral, and derivative coefficients, respectively.

[0080] In this embodiment, for proportional-integral-derivative (PID) control, initial control commands are generated based on the pressure control values ​​of each control region. PID control is the most widely used classic control algorithm in industrial control, possessing advantages such as simple structure, convenient parameter tuning, and strong robustness. Among them, the proportional term... The control quantity is output proportionally to the current deviation; the larger the deviation, the stronger the adjustment, used to quickly reduce the deviation. (Integral term) Integrating past deviations eliminates steady-state errors, ensuring the clamping force remains stable at the target value during long-term pressure holding; the differential term... The control quantity is output based on the rate of change of the deviation to predict the trend of deviation change and suppress overshoot and oscillation. In this embodiment, considering the slow time-varying characteristics of the electrolytic cell clamping force control, the integral action can be appropriately increased and the derivative action decreased to ensure pressure holding stability. Each control region in this embodiment can have its PID parameters independently set to adapt to the stiffness characteristics and response speed of different regions, achieving optimal control performance.

[0081] In another optional embodiment, when the control strategy is sliding mode variable structure control, the step of generating corresponding control commands based on the pressure control values ​​of each control region further includes: A sliding surface function is constructed, which is a linear combination of the pressure control value and the derivative of the pressure control value with respect to time, wherein the pressure control value corresponds to a preset sliding surface slope coefficient; based on the sliding surface function, corresponding control commands are generated according to the set sub-control strategy.

[0082] Specifically, when the control strategy is sliding mode variable structure control, the step of generating corresponding control commands based on the pressure control values ​​of each control region further includes:

[0083] in, For sliding surface functions, This is the slope coefficient of the sliding surface. The derivative of the pressure control value of the control area with respect to time; In an optional embodiment, based on the sliding mode surface function, corresponding control commands are generated using a relay-type sub-control strategy:

[0084] in, K To switch the gain, It is a symbolic function.

[0085] Sliding mode variable structure control is a nonlinear control algorithm whose core characteristic is that the system state slides at high frequency along a preset sliding surface, eventually converging to an equilibrium point. Compared to PID control, sliding mode control has stronger anti-interference capabilities and robustness, and can better adapt to uncertainties such as parameter changes and external disturbances during the operation of the electrolytic cell, making it particularly suitable for scenarios with large load fluctuations and frequent changes in operating conditions. In this embodiment, a reaching law (such as an exponential reaching law or a power reaching law) is designed to suppress the chattering problem of sliding mode control, ensuring smooth control output and avoiding wear and lifespan reduction caused by frequent actuator movements. Meanwhile, in response to the operating characteristics of the electrolyzer, a relay-type sliding mode variable structure is adopted for control: when the hydrogen production system enters the sliding surface, its dynamic motion characteristics are determined only by the preset sliding surface parameters, and are unrelated to changes in the parameters of the hydrogen production system itself or external load disturbances. Compared with PID control that relies on a precise object model, this strategy does not require repeated tuning of control parameters with temperature and aging degree. It can maintain stable control accuracy under all operating conditions such as cold start-up and load jumps, effectively avoiding overshoot, oscillation, and even instability problems that are prone to occur in traditional linear control when operating conditions fluctuate, and ensuring that the clamping force remains stable within the target range for a long time.

[0086] In another optional embodiment, based on the sliding surface function, corresponding control commands are generated using a saturated function type as a sub-strategy:

[0087] in, K To switch gain, For boundary layer thickness, It is a saturation function. , These are the normalized synovial surface state values. It is the ratio of the degree to which the current state of the hydrogen production system deviates from the sliding surface to the preset boundary layer thickness.

[0088] In this embodiment, based on sliding mode variable structure control, and considering the operating characteristics of the electrolyzer, a saturated function-type sliding mode variable structure is used for control, divided into three working intervals. When (| |> (i.e. | When |>1, the hydrogen production system is outside the preset boundary layer, and the saturation function outputs a saturation value of ±1. At this time, the control effect is basically the same as that of the relay type, with full-amplitude switching gain. K Output control quantity to drive the system to quickly approach the sliding surface; when | |≤ (i.e. | When |≤1, the hydrogen production system enters the boundary layer near the sliding surface, and the saturation function output is a linear value proportional to the sliding surface value. This replaces the relay-type switching output with a linear continuous output, achieving a smooth transition. This embodiment, while retaining the strong robustness of sliding mode control, further addresses the high-frequency chattering problem, effectively extending the service life of actuators and seals. It also improves response speed and steady-state stability, adapting to all operating conditions and control requirements.

[0089] It should be noted that the above embodiments are only used to illustrate the specific implementation of this application. This application supports compatibility with multiple control algorithms. Those skilled in the art should adapt to the needs of different application scenarios according to actual application requirements, and will not elaborate further here.

[0090] To further improve the safe and stable operation of the hydrogen production system, in an optional embodiment, before generating corresponding control commands based on the pressure control values ​​of each control zone, the electrolyzer clamping force adjustment method further includes: calculating a creep relaxation compensation command based on the pressure holding time t when the hydrogen production system is in a pressure holding state, according to a pre-set creep relaxation feedforward compensation unit; the creep relaxation compensation command is:

[0091] in, This is a creep relaxation compensation command in the continuous time domain. This is the maximum creep compensation amplitude allowed by the system. The base of the natural logarithm, The structural creep decay time constant of the clamping end plate; The step of generating corresponding control commands based on the pressure control values ​​of each control zone further includes: superimposing the creep relaxation compensation command onto the control command.

[0092] In this embodiment, considering that during the long-term pressure holding process of the electrolytic cell, the sealing gasket (rubber, PTFE, and other polymer materials) will undergo viscoelastic creep, and the metal structures such as the clamping end plate and bolts will also undergo slow stress relaxation, both of which together cause the clamping force to gradually decrease over time. If only feedback control is used, pressure replenishment will only be initiated after the clamping force drops to the deviation threshold, which is a post-event compensation; while feedforward compensation is based on the creep law to actively predict the clamping force decay trend and gradually increase the clamping force in advance, which is a pre-event prevention. The stress relaxation law of polymer materials conforms to the exponential decay model, that is, the relaxation rate is fast in the early stage of pressure holding, and the clamping force decreases significantly; as time goes by, the relaxation rate gradually slows down and eventually approaches a stable value. The exponential model used in this embodiment accurately fits this physical law, and the compensation amount gradually increases over time, with the rate of increase slowing down, eventually approaching the maximum compensation amplitude, which completely corresponds to the actual creep decay trend.

[0093] This embodiment pre-calibrates the creep relaxation compensation command through long-term pressure holding experiments, and writes the calibration parameters into the controller. The system can then superimpose feedforward compensation during the pressure holding process. This embodiment combines creep relaxation feedforward compensation with feedback closed-loop control, enabling the hydrogen production system to respond quickly to sudden pressure fluctuations while actively offsetting long-term, slow creep decay, significantly extending the pressure holding period and reducing the frequency of manual maintenance. This embodiment further improves the stability of the control command by setting creep relaxation compensation commands. Experimental verification shows that after adopting feedforward compensation, the pressure holding period under the same leakage standard can be extended by more than 5 times, thereby significantly reducing operation and maintenance costs.

[0094] To further improve the safe and stable operation of the hydrogen production system, in an optional embodiment, after generating corresponding control commands based on the pressure control values ​​of each control zone, and before driving the corresponding actuators to independently adjust the clamping force of the corresponding control zone according to the control commands, the electrolyzer clamping force adjustment method further includes: The control command after the superimposed creep relaxation compensation command is clamped according to the preset safety limiting unit, and the control command is constrained between the preset soft protection lower limit command and the soft protection upper limit command to obtain the final control command; the soft protection lower limit command and the soft protection upper limit command are both lower than the corresponding pressure hard threshold of the system.

[0095] Specifically, the control command is amplitude clamped according to the preset safety limiting unit:

[0096] in, A soft protection lower limit command is pre-set for the hydrogen production system, indicating a pressure below the hard threshold. A soft protection upper limit command is pre-set for hydrogen production systems, allowing protection levels below the hard pressure threshold. For updated control commands, This is the amplitude limiting function.

[0097] In this embodiment, the safety limit is the first line of soft protection for the system. Its upper and lower limits are both lower than the hardware hard thresholds of the equipment, such as the maximum pressure of the hydraulic cylinder or the ultimate bearing capacity of the clamping end plate. During normal operation, the control quantity fluctuates within the upper and lower limits, and the limiting function is not triggered. However, in extreme cases such as sensor failure, algorithm anomalies, or communication interference, which cause the calculated control quantity to be abnormally large or small, the limiting function will forcibly constrain the output within a safe range. This embodiment uses a safety limit to update the control command, thereby preventing the actuator from damaging the core components of the fuel cell stack due to excessive output pressure or causing serious leakage due to excessively low output pressure.

[0098] Thus, the electrolyzer clamping force adjustment is completed. In this embodiment, the clamping end plate is divided into zones, and a distributed control architecture is formed by the sensor arrays corresponding to each zone and the independent actuators. During operation, the sensor groups in each zone first collect sensing signals. After temperature drift interference is eliminated by a preset pressure mapping and temperature compensation model, the true clamping force of each zone is obtained, ensuring the accuracy of measurement data under high-temperature conditions. Then, a dual-coupling and decoupling mechanism is constructed by combining the spatial geometric distance between zones and the real-time temperature difference. When calculating the pressure deviation, the neighboring stress linkage effect and thermal stress interference of the rigid end plate are actively offset, avoiding global stress fluctuations caused by local adjustments. Finally, the corresponding control commands are output by the independent actuators in each zone to achieve closed-loop precise control of the end plate clamping force. This embodiment, through the synergistic effect of various components of the hydrogen production system, can form an edge-priority gradient clamping force field to improve sealing reliability, and can maintain stable clamping force for a long time, effectively extending the pressure holding period and reducing leakage risk and maintenance costs.

[0099] Based on the electrolytic cell clamping force adjustment method of the above embodiments, another embodiment of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the following: dividing the clamping end plate into multiple control areas, each control area corresponding to at least one sensor group and at least one actuator; receiving sensing signals collected by the sensor groups of each control area, obtaining the actual clamping force received by the control area according to a preset pressure mapping model and a temperature compensation model; decoupling and weighting the pressure difference between the actual clamping force of each control area and a preset target pressure value according to the spatial geometric distance between each control area and the real-time temperature difference of each control area, and obtaining the corrected pressure control value of each control area; generating corresponding control commands according to the pressure control values ​​of each control area, and driving the corresponding actuators to independently adjust the clamping force of the corresponding control area according to the control commands.

[0100] In practical applications, the computer-readable storage medium can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. For example, a computer-readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this embodiment, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0101] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0102] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0103] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0104] like Figure 11 As shown, another embodiment of the present invention provides a structural schematic diagram of a computer device. Figure 11 The computer device T12 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0105] like Figure 11 As shown, the computer device T12 is represented in the form of a general-purpose computing device. The components of the computer device T12 may include, but are not limited to: one or more processors or processor units T16, system memory T28, and bus T18 connecting different system components (including system memory T28 and processor unit T16).

[0106] Bus T18 represents one or more of several bus architectures, including memory buses or memory controllers, peripheral buses, graphics acceleration ports, processors, or local buses using any of the various bus architectures. Examples of these architectures include, but are not limited to, Industry Standard Architecture (ISA) buses, Micro Channel Architecture (MAC) buses, Video Electronics Standards Association (VESA) local buses, and Peripheral Component Interconnect (PCI) buses.

[0107] Computer device T12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by computer device T12, including volatile and non-volatile media, removable and non-removable media.

[0108] System memory T28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) T30 and / or cache memory T32. Computer device T12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system T34 may be used to read and write non-removable, non-volatile magnetic media (…). Figure 11 Not shown; usually referred to as a "hard drive"). Although Figure 11 Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk") and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to the bus T18 via one or more data media interfaces. The system memory T28 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of the present invention.

[0109] A program / utility T40 having a set (at least one) of program modules T42 can be stored, for example, in system memory T28. Such program modules T42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. Program modules T42 typically perform the functions and / or methods described in the embodiments of the present invention.

[0110] Computer device T12 can also communicate with one or more external devices T14 (e.g., keyboard, pointing device, display T24, etc.), and with one or more devices that enable a user to interact with computer device T12, and / or with any device that enables computer device T12 to communicate with one or more other computing devices (e.g., network card, modem, etc.). This communication can be performed through input / output (I / O) interface T22. Furthermore, computer device T12 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) through network adapter T20. Figure 11 As shown, network adapter T20 communicates with other modules of computer device T12 via bus T18. It should be understood that, although... Figure 11 As not shown, it can be used in conjunction with computer device T12 with other hardware and / or software modules, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0111] The processor unit T16 executes various functional applications and data processing by running programs stored in the system memory T28, such as implementing an electrolytic cell clamping force adjustment method provided in an embodiment of the present invention.

[0112] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A hydrogen production system, characterized in that, Includes an electrolytic cell and a clamping force adjustment device, wherein, The electrolytic cell includes two clamping end plates arranged opposite each other, and an electrolytic unit group stacked between the two clamping end plates. At least one of the clamping end plates has a sensor array on its surface away from the electrolytic unit group. The sensor array includes multiple sensor groups, each of which includes: a strain sensing unit for collecting strain signals of the control area corresponding to the clamping end plate, and a temperature sensing unit for collecting real-time temperature signals of the control area corresponding to the clamping end plate. The clamping force adjusting device includes a controller and multiple independently controlled actuators. The actuators act on the clamping end plate equipped with a sensor array. The controller is configured to: The clamping end plate is divided into multiple control areas, each control area corresponding to at least one sensor group and at least one of the actuators; Receiving sensing signals collected by sensor groups in each control area, and obtaining the actual clamping force received in the control area according to a preset pressure mapping model and temperature compensation model, further includes: According to the pre-set pressure mapping model, the strain deformation signal collected by the strain sensing unit is mapped into the sensing clamping force. The pressure mapping model adopts a third-order polynomial mapping relationship, takes the strain deformation signal as input, takes the pre-calibrated polynomial mapping regression coefficient as parameters, and outputs the sensing clamping force at the corresponding coordinate position by weighted summation of constant term, first strain term, second strain term and third strain term. According to the preset temperature compensation model, the real-time temperature signal collected by the temperature sensing unit is used to correct the temperature drift of the sensed clamping force to obtain the actual clamping force. The temperature compensation model takes the difference between the real-time temperature and the temperature reference point as input, calculates the temperature drift deviation correction factor through a third-order polynomial, and then makes a proportional correction to the sensed clamping force based on the temperature drift deviation correction factor to output the actual clamping force at the corresponding coordinate position. Based on the spatial geometric distance between each control zone and the real-time temperature difference between each control zone, the pressure difference between the actual clamping force and the preset target pressure value in each control zone is decoupled and weighted to obtain the corrected pressure control value for each control zone. This further includes: The average clamping force difference between each control area is calculated based on the actual clamping force at each coordinate point in each control area and the preset target pressure value of the control area. This further includes: using the difference between the target pressure value and the actual clamping force at each coordinate point in each control area as the pressure difference value for that coordinate point; integrating the pressure differences of all coordinate points in the control area by the area of ​​that control area to obtain the average clamping force difference value for that control area; the spatial and thermal field coupling coefficient is used to characterize the degree of stress linkage influence between adjacent control areas, and is obtained by a weighted sum of the mechanical stiffness coupling term and the thermal stress coupling term; wherein, the mechanical stiffness coupling term and the two control areas... The spatial geometric distance between the center points of the control areas is inversely proportional to the average physical distance between the center points of all adjacent areas. This distance is normalized and multiplied by a pre-set mechanical stiffness coupling weight. The thermal stress coupling term is directly proportional to the real-time temperature difference between the two control areas. This term is normalized based on the difference between the highest and lowest temperatures across the entire pressure plate area and multiplied by a pre-set thermal stress coupling weight. The pressure control value is based on the average pressure difference between the corresponding control areas, plus a coupling correction between the control area and all adjacent control areas. This coupling correction is the product of the coupling coefficient of the corresponding adjacent areas and the difference between the average pressure difference between the two areas. The spatial and thermal field coupling coefficient is calculated based on the spatial geometric distance between each control area and the real-time temperature difference between each control area. The pressure control value of each control area is obtained based on the average clamping force difference of each control area and the spatial and thermal field coupling coefficient. Based on the pressure control value of each control zone, corresponding control commands are generated, and the corresponding actuators are driven to independently adjust the clamping force of the corresponding control zone according to the control commands. The electrolytic cell also includes multiple pressure sensors disposed on the surface of the clamping end plate near the electrolytic unit group. Each control area corresponds to at least one pressure sensor. The pressure sensors are used to collect in-situ measured pressure values ​​of the control area to calibrate the pressure mapping model.

2. A method for adjusting the clamping force of an electrolyzer in a hydrogen production system as described in claim 1, characterized in that, include: The clamping end plate is divided into multiple control areas, each control area corresponding to at least one sensor group and at least one actuator; The system receives sensing signals collected by sensor groups in each control area, and obtains the actual clamping force received in each control area according to a preset pressure mapping model and temperature compensation model. The sensor group includes a strain sensing unit and a temperature sensing unit. The system further includes: mapping the strain deformation signal collected by the strain sensing unit into a sensed clamping force according to a preset pressure mapping model; the pressure mapping model uses a third-order polynomial mapping relationship, taking the strain deformation signal as input and pre-calibrated polynomial mapping regression coefficients as parameters, and outputting the sensed clamping force at the corresponding coordinate position through a weighted summation of constant terms, first-order strain terms, second-order strain terms, and third-order strain terms; and according to a preset temperature compensation model... The temperature sensing unit collects real-time temperature signals to correct temperature drift in the sensed clamping force, thus obtaining the actual clamping force. The temperature compensation model takes the difference between the real-time temperature and the temperature reference point as input, calculates the temperature drift deviation correction factor using a third-order polynomial, and then proportionally corrects the sensed clamping force based on the temperature drift deviation correction factor to output the actual clamping force at the corresponding coordinate position. The electrolytic cell also includes multiple pressure sensors disposed on the surface of the clamping end plate near the electrolytic unit group. Each control area corresponds to at least one pressure sensor. The pressure sensors are used to collect in-situ measured pressure values ​​of the control area to calibrate the pressure mapping model. Based on the spatial geometric distance between each control zone and the real-time temperature difference between each control zone, the pressure difference between the actual clamping force and the preset target pressure value in each control zone is decoupled and weighted to obtain the corrected pressure control value for each control zone. This further includes: The average clamping force difference between each control area is calculated based on the actual clamping force at each coordinate point in each control area and the preset target pressure value of the control area. This further includes: using the difference between the target pressure value and the actual clamping force at each coordinate point in each control area as the pressure difference value for that coordinate point; integrating the pressure differences of all coordinate points in the control area by the area of ​​that control area to obtain the average clamping force difference value for that control area; the spatial and thermal field coupling coefficient is used to characterize the degree of stress linkage influence between adjacent control areas, and is obtained by a weighted sum of the mechanical stiffness coupling term and the thermal stress coupling term; wherein, the mechanical stiffness coupling term and the two control areas... The spatial geometric distance between the center points of the control areas is inversely proportional to the average physical distance between the center points of all adjacent areas. This distance is normalized and multiplied by a pre-set mechanical stiffness coupling weight. The thermal stress coupling term is directly proportional to the real-time temperature difference between the two control areas. This term is normalized based on the difference between the highest and lowest temperatures across the entire pressure plate area and multiplied by a pre-set thermal stress coupling weight. The pressure control value is based on the average pressure difference between the corresponding control areas, plus a coupling correction between the control area and all adjacent control areas. This coupling correction is the product of the coupling coefficient of the corresponding adjacent areas and the difference between the average pressure difference between the two areas. The spatial and thermal field coupling coefficient is calculated based on the spatial geometric distance between each control area and the real-time temperature difference between each control area. The pressure control value of each control area is obtained based on the average clamping force difference of each control area and the spatial and thermal field coupling coefficient. Based on the pressure control value of each control zone, corresponding control commands are generated, and the corresponding actuators are driven to independently adjust the clamping force of the corresponding control zone according to the control commands.

3. The method for adjusting the clamping force of an electrolytic cell according to claim 2, characterized in that, When the control strategy is proportional-integral-derivative (PID) control, the step of generating corresponding control commands based on the pressure control values ​​of each control region further includes: taking the pressure control value as input, calculating the proportional term, integral term, and derivative term respectively, and then summing them to obtain the control command; the proportional term is the product of the pressure control value and a preset proportional coefficient, the integral term is the product of the integral of the pressure control value with respect to time and a preset integral coefficient, and the derivative term is the product of the derivative of the pressure control value with respect to time and a preset derivative coefficient; When the control strategy is sliding mode variable structure control, the step of generating corresponding control commands based on the pressure control values ​​of each control region further includes: constructing a sliding surface function, wherein the sliding surface function is composed of a linear combination of the pressure control value and the derivative of the pressure control value with respect to time, wherein the pressure control value corresponds to a preset sliding surface slope coefficient; and generating corresponding control commands based on the sliding surface function and the set sub-control strategy.

4. The method for adjusting the clamping force of an electrolytic cell according to claim 2, characterized in that, Before generating corresponding control commands based on the pressure control values ​​of each control zone, the electrolytic cell clamping force adjustment method further includes: According to the pre-set creep relaxation feedforward compensation unit, when the hydrogen production system is under pressure holding, the creep relaxation compensation command is calculated based on the pressure holding time. The creep relaxation compensation command follows an exponential change law and gradually approaches the maximum creep compensation amplitude allowed by the system as the pressure holding time increases. The rate of change is determined by the pre-set creep decay time constant of the pressure end plate structure. The step of generating corresponding control commands based on the pressure control values ​​of each control zone further includes: superimposing the creep relaxation compensation command into the control command.

5. The method for adjusting the clamping force of an electrolytic cell according to claim 4, characterized in that, After generating corresponding control commands based on the pressure control values ​​of each control zone, and before driving the corresponding actuators to independently adjust the clamping force of the corresponding control zones according to the control commands, the electrolytic cell clamping force adjustment method further includes: The control command after the superimposed creep relaxation compensation command is clamped according to the preset safety limiting unit, and the control command is constrained between the preset soft protection lower limit command and the soft protection upper limit command to obtain the final control command; the soft protection lower limit command and the soft protection upper limit command are both lower than the corresponding pressure hard threshold of the system.

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