Electrolytic cell system and control method with fault prediction and automatic isolation functions

Abstract

This invention discloses an electrolytic cell system and control method with fault prediction and automatic isolation functions. The system includes: a data acquisition module for real-time acquisition of the individual cell voltage, electrolyte temperature, electrolytic cell operating current, and cell pressure of each electrolytic cell; a fault isolation system configured in the electrical and fluid circuits of each electrolytic cell for independent fault isolation of individual abnormal electrolytic cells; and a safety control unit connected to the data acquisition module, the fault isolation system, and the electrolytic cell main power supply. The safety control unit is configured to immediately shut down the electrolytic cell main power supply and activate the fault isolation system when the individual cell voltage of any electrolytic cell is greater than or equal to the individual cell voltage safety threshold, thereby disconnecting the electrical and fluid circuits of the electrolytic cell with the excessive voltage. This invention enables rapid recovery of the electrolytic cell after fault isolation within 4 seconds, significantly reducing production downtime losses.

Description

Technical Field

[0001] This invention relates to the field of electrolytic cells for hydrogen production, chlor-alkali industry and water treatment, and specifically to an electrolytic cell system and control method with fault prediction and automatic isolation functions. Background Technology

[0002] Electrolyzers typically consist of dozens to hundreds of unit cells (referred to as electrolysis cells or cells) connected in series. Each cell contains an anode, a cathode, and a diaphragm or membrane electrode assembly. During long-term operation, individual cells may experience abnormal voltage increases or decreases, reduced gas production, or reverse current due to catalyst deactivation, membrane perforation, electrode short circuits, blockage of the inlet pipe, or obstruction of the gas passage. Among these, an increase in individual cell voltage is the most direct symptom of failure—when the voltage reaches above 2.5V, it indicates that the cell is in a severely abnormal state. Continued operation will lead to a sharp increase in energy consumption, the generation of hot spots that burn out the diaphragm, and even a hydrogen-oxygen mixture explosion.

[0003] Traditional methods require shutting down, purging, and disassembling the entire electrolyzer to locate and replace the faulty chamber, followed by reassembly, pressure testing, and activation. This process typically takes 2-7 days. For large chlor-alkali electrolyzers or megawatt-scale hydrogen production electrolyzers, a single shutdown can result in losses ranging from hundreds of thousands to millions of yuan. Furthermore, the disassembly process can easily damage the sealing gaskets of adjacent chambers, leading to new leaks after reassembly.

[0004] To address the above issues, one possible solution is to short-circuit the two electrodes of the faulty chamber with an external wire. However, this solution has the following drawbacks: First, it relies on manual judgment and operation, resulting in a long response time. Second, it lacks a tiered early warning mechanism, making it impossible to intervene in advance before the fault worsens. Third, it only achieves electrical bypass without cutting off the electrolyte supply to the faulty chamber, posing a safety hazard. Fourth, it does not form a complete closed-loop system from data acquisition to automatic execution.

[0005] Therefore, there is an urgent need in this field for a technical solution that can isolate fault cells without disassembling the electrolytic cell and under conditions of no production stoppage or short-term load reduction. Summary of the Invention

[0006] To address the aforementioned problems, this invention proposes an electrolytic cell system with fault prediction and automatic isolation functions. This system aims to solve the technical problems of existing electrolytic cells, such as delayed response to individual electrolysis chamber faults, the need for manual judgment, the ability to only implement a single bypass, and inadequate safety protection. The specific technical solution is as follows: An electrolytic cell system with fault prediction and automatic isolation functions includes: The main body of the electrolytic cell includes multiple electrolytic cells connected in series. Each electrolytic cell has a positive terminal and a negative terminal, and adjacent electrolytic cells are connected in series through an internal conductor. The data acquisition module is used to collect the individual voltage, electrolyte temperature, electrolytic cell operating current, and cell pressure of each electrolysis cell in real time. The fault isolation system, configured in the electrical and fluid circuits of each electrolysis cell, is used to perform independent fault isolation for individual abnormal electrolysis cells; The safety control unit is connected to the data acquisition module, the fault isolation system, and the main power supply of the electrolytic cell, respectively. The safety control unit is configured to: immediately shut down the main power supply of the electrolytic cell when the voltage of any individual cell in the electrolysis chamber is greater than or equal to the safe threshold voltage of the individual cell, and start the fault isolation system to cut off the electrical circuit and fluid circuit of the electrolysis chamber with the voltage exceeding the limit, thereby achieving fault isolation.

[0007] Preferably, the safe threshold for the individual cell voltage is 2.5V, the sampling frequency of the data acquisition module is ≥10Hz, and the individual cell voltage measurement accuracy is ≤±0.5%, the electrolyte temperature measurement accuracy is ≤±0.5℃, and the tank pressure measurement accuracy is ≤±1%FS.

[0008] As a further improvement, the electrolytic cell system of the present invention with fault prediction and automatic isolation functions further includes an index prediction module connected to the data acquisition module, used to predict, provide graded early warning and anomaly identification of the operating status of the electrolysis chamber based on the acquired parameters, and includes: The reference threshold unit has a preset individual cell voltage safety threshold of 2.5V; The trend prediction unit is used to predict the aging, short circuit, membrane fouling or electrolyte abnormality trends of the electrolysis chamber based on the rate of voltage change. The graded early warning unit has built-in multi-level early warning thresholds: Level 1 warning: Individual cell voltage ≥ 2.3V or tank voltage fluctuation ≥ ±10%; Level 2 warning: Individual cell voltage ≥ 2.4V or electrolyte temperature ≥ 85℃ or tank pressure ≥ 1.2 times the normal value; Level 3 action: Individual cell voltage ≥ 2.5V.

[0009] Preferably, the indicator prediction module is also equipped with a voltage change rate monitoring unit. When the voltage of any single cell in the electrolysis chamber rises at a rate ≥0.5V / s within 1 second, a rapid warning is triggered and the safety control unit is notified to strengthen monitoring.

[0010] Preferably, the fault isolation system includes: Electrical isolation unit: a spare terminal block configured at the positive and negative terminals of each electrolysis cell, which is fixed in parallel with the positive and negative terminals respectively; and one or more low-resistance bypass wires that can be automatically connected to the spare terminal block, for cutting off the power supply to the abnormal electrolysis cell by bypassing and short-circuiting the abnormal electrolysis cell, so as to remove it from the series working queue. Fluid isolation unit: Automatic shut-off valves configured on the inlet and outlet pipes of each electrolysis chamber are used to close the electrolyte inlet and outlet channels of the chamber, thereby achieving fluid isolation.

[0011] The liquid inlet pipe includes an anode liquid inlet pipe and a cathode liquid inlet pipe, and the liquid outlet pipe includes an anode liquid outlet pipe and a cathode liquid outlet pipe.

[0012] Preferably, the spare terminal has a copper-plated silver or copper-plated tin anti-corrosion layer on its surface and is equipped with an openable waterproof and dustproof insulating cover; the spare terminal is fixedly connected to the positive or negative terminal by copper bolts, and the contact resistance at the connection is ≤0.001Ω.

[0013] Preferably, the bypass wire has a resistance less than 1 / 10 of the resistance of the isolated cell, a length of 0.8m to 1.5m, is made of copper or copper alloy, and has a cross-sectional area ≥50 mm². 2 The bypass conductor is covered with an insulating sheath resistant to electrolyte corrosion, and the insulating sheath is made of EPDM rubber, PTFE or silicone rubber.

[0014] Preferably, the electrical isolation unit further includes an electrical isolation mechanism disposed at both ends of the bypass conductor and matched with the spare terminal block. The electrical isolation mechanism is a quick-connect connector, or one or a combination of a controllable switch or a fast-switching knife switch.

[0015] The quick-connector is one of a plug-in elastic clip, a bolt fastening clip, or a quick-locking connector; the bypass wire body between the two quick-connectors has a flexible braided structure or a rigid copper busbar structure.

[0016] Preferably, the fluid isolation unit is an electric shut-off valve, a pneumatic diaphragm valve, or a solenoid valve, which is directly driven by the safety control unit. The valve closing time is ≤1 second, and the leakage level is not lower than ANSI Class V.

[0017] Furthermore, the safety control unit is equipped with a manual safety control mode and an automatic safety control mode. When switched to the manual safety control mode, a single unit voltage ≥2.5V will only trigger a shutdown and alarm, and will not automatically perform fault isolation.

[0018] Furthermore, after performing shutdown and fault isolation actions, the safety control unit synchronously generates a fault record, marking the abnormal electrolysis chamber number, over-limit voltage value, occurrence time, and fault isolation action status.

[0019] Furthermore, when multiple electrolysis chambers simultaneously experience a voltage ≥2.5V, the safety control unit executes an emergency shutdown of the entire machine and simultaneously initiates fault isolation for all over-limit electrolysis chambers.

[0020] An electrolytic cell system with fault prediction and automatic isolation functions according to the present invention also includes an HMI human-machine interface, which is connected to the safety control unit and is used to display the individual voltage, electrolyte temperature, cell pressure data and fault isolation status of each electrolysis cell in real time, and supports historical data query and parameter setting.

[0021] An electrolytic cell safety control method for an electrolytic cell system with fault prediction and automatic isolation functions includes the following steps: S1. Real-time acquisition of individual cell voltages in each electrolysis chamber; S2, the indicator prediction module performs real-time analysis and trend prediction of individual unit voltage data; S3. Determine if there is a single cell voltage ≥2.5V in the electrolytic cell; S4. If the conditions are met, the safety control unit immediately shuts down the electrolytic cell and activates the fault isolation system to electrically and fluidly isolate the electrolytic cell with the voltage exceeding the limit. S5. After isolation is completed, maintain a safe state and wait for manual reset or automatic system re-inspection.

[0022] Preferably, in step S2, the indicator prediction module issues an early warning based on the rise slope of the individual unit voltage to avoid protection delay caused by sudden voltage jumps.

[0023] Furthermore, once the fault isolation is completed, the system is prohibited from re-entering the electrolysis chamber until the fault is eliminated and manually confirmed to be reset.

[0024] The beneficial effects of this invention are: Complete closed-loop automatic control: From data acquisition and indicator prediction to shutdown, isolation and recovery, a fully automatic closed loop is formed, requiring no manual intervention and with a response time of ≤4 seconds.

[0025] Tiered early warning and early intervention: Through the first and second level early warning mechanisms, maintenance personnel can be alerted before the fault deteriorates to 2.5V, so as to avoid sudden downtime.

[0026] Double isolation ensures safety and reliability: simultaneously cutting off the electrical circuit (bypass) and the fluid circuit (valve shut-off), the fault chamber is completely isolated, with no current and no liquid flow, eliminating the risk of hydrogen-oxygen mixture explosion.

[0027] Voltage change rate auxiliary criterion: covers rapidly deteriorating faults such as instantaneous short circuits, avoiding missed detections.

[0028] Manual and automatic modes can be switched: to meet the needs of different operation and maintenance scenarios and improve system flexibility.

[0029] High compatibility: Suitable for various series-connected electrolysis equipment such as alkaline water electrolyzers, PEM electrolyzers, and chlor-alkali ion membrane electrolyzers.

[0030] Significantly reduce downtime losses: Traditional dismantling and repair requires several days of downtime, while this solution only requires a few seconds of isolation. Through 4-second fault isolation, the electrolytic cell can be quickly restored to operation under fault isolation conditions, reducing downtime losses by more than 99%. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of an electrolytic cell system with fault prediction and automatic isolation functions according to the present invention. Figure 2 yes Figure 1 A magnified view of a portion of the fluid isolation unit. Figure 3 yes Figure 1 A magnified view of a portion of the electrical isolation unit section; Figure 4 This is a flowchart illustrating the overall logic control of a safety control method for an electrolytic cell system with fault prediction and automatic isolation functions according to the present invention. Figure 5 yes Figure 4 The flowchart of the 4-second fast fault isolation timing control.

[0032] In the diagram: 1. Electrolytic cell body; 2. Electrolysis chamber; 3. Positive terminal; 4. Negative terminal; 5. Spare terminal; 6. Fault isolation system; 7. Electrical circuit; 8. Fluid circuit; 9. Electrical isolation unit; 10. Bypass wire; 11. Fluid isolation unit; 12. Inlet pipe; 13. Outlet pipe; 14. Automatic shut-off valve; 15. Electrical isolation mechanism (quick-connector); 16. Main inlet pipe; 17. Anode outlet pipe; 18. Cathode outlet pipe; 19. Anode chamber; 20. Cathode chamber; 21. Elastic support mesh; 22. Diaphragm; 23. Electrode mesh; 24. Main power line; 25. Hall current sensor; 26. Pressure sensor; 27. Thermocouple; 28. Data acquisition module; 29. ​​Index prediction module; 30. Safety control unit. 31. Baseline threshold unit; 32. Trend prediction unit; 33. Hierarchical early warning unit; 34. Voltage change rate monitoring unit; 35. HMI (Human-Machine Interface). Detailed Implementation

[0033] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0034] Example 1: like Figures 1 to 5 The figure shown is an embodiment of an electrolytic cell system with fault prediction and automatic isolation functions according to the present invention, comprising: Electrolytic cell body 1 It consists of multiple electrolytic cells 2 connected in series. Each cell contains an anode, a cathode, a diaphragm 22 and an electrode plate. Adjacent electrolytic cells 2 are electrically connected in series through internal conductors. Each cell has a spare terminal 5 connected in parallel to its positive terminal 3 and negative terminal 4 for connecting an external bypass wire 10.

[0035] Data acquisition module 28 Data acquisition module 28 is the system's sensing layer, which synchronously acquires the following parameters of all electrolysis chambers 2 at a frequency of not less than 10Hz: Individual cell voltage: Reflects the change in internal resistance and membrane state of electrolysis cell 2, and is a core parameter for fault prediction; measurement accuracy ≤ ±0.5%. Operating current: used to calculate voltage-current characteristics and assist in judging abnormal internal resistance; the total current is collected through Hall current sensor 25 or shunt. Electrolyte temperature: Abnormal electrolyte temperature (such as local overheating) is often a precursor to membrane perforation or short circuit; thermocouples 27 are installed at the inlet and outlet or electrode of each electrolysis chamber 2, with a measurement accuracy of ≤±0.5℃; Tank pressure: An abnormally high tank pressure may indicate a blockage in the gas passage or hydrogen-oxygen cross-contamination. Measurement accuracy ≤ ±1%FS; The data collected by the data acquisition module 28 is transmitted to the indicator prediction module 29 via the isolation transmitter to ensure safe isolation between the high-voltage and low-voltage circuits.

[0036] Indicator Prediction Module 29 The indicator prediction module 29 is the system's analysis layer. It is connected to the data acquisition module 28 and performs prediction, graded early warning, and anomaly identification on the operating status of the electrolysis chamber 2 based on the acquired parameters. It includes: Reference threshold unit 31 has a preset single-cell voltage safety threshold of 2.5V; Trend prediction unit 32 is used to predict the aging, short circuit, membrane fouling or electrolyte abnormality trend of electrolysis chamber 2 based on the rate of change of individual cell voltage. The graded early warning unit 33 has built-in multi-level early warning thresholds: Level 1 Warning (Attention): Individual cell voltage ≥ 2.3V or tank voltage fluctuation ≥ ±10%, record the event, HMI human-machine interface prompts at 35, do not trigger automatic action; Level 2 warning (alarm): Individual cell voltage ≥2.4V or temperature ≥85℃ or pressure ≥1.2 times the normal value, audible and visual alarm, it is recommended to reduce load and pre-start the isolation system (fault isolation system 6 enters standby state, but does not automatically perform isolation). Level 3 Action (Shutdown and Isolation): When the individual unit voltage is ≥2.5V, the safety control unit 30 is triggered to perform shutdown and isolation actions.

[0037] In addition, the indicator prediction module 29 is also equipped with a voltage change rate monitoring unit 34: when the voltage of any electrolysis chamber 2 rises at a rate ≥0.5V / s within 1 second, a rapid warning is triggered and the safety control unit 30 is notified to strengthen monitoring; this function can capture rapidly deteriorating faults such as instantaneous short circuits.

[0038] Fault Isolation System 6 Fault isolation system 6 is the system's execution layer. It is configured in the electrical circuit 7 and fluid circuit 8 of each electrolysis cell 2 to perform independent fault isolation for individual abnormal electrolysis cells 2, including: Electrical isolation unit 9: Each compartment has a pre-installed spare terminal 5 (copper plated with silver or copper plated with tin for corrosion protection) on the positive terminal 3 and negative terminal 4, and is equipped with one or more low-resistance bypass wires 10 that can be automatically connected to the spare terminal 5; the bypass wires 10 are made of copper or copper alloy and have a cross-sectional area ≥50mm². 2 The resistance is less than 1 / 10 of the resistance of the isolated cell. Both ends are equipped with an electrical isolation mechanism 15 that matches the spare terminal 5, i.e., an automatic quick-connect connector (electromagnetic drive type, pneumatic type or shape memory alloy type). When isolation is required, the automatic quick-connect connector connects one end of the bypass wire 10 to the spare terminal 5 of the positive terminal 3 of the faulty electrolytic cell 2, and the other end to the spare terminal 5 of the negative terminal 4 of the faulty electrolytic cell 2, forming a bypass short circuit of the faulty electrolytic cell 2, so that the current bypasses the faulty cell and is directly applied to the next electrolytic cell 2. Fluid isolation unit 11: Automatic shut-off valves 14 are installed on the inlet pipe 12 and outlet pipe 13 of each electrolysis chamber 2. The valves are electric shut-off valves or pneumatic ball valves. The valve closing time is ≤1 second and the leakage level is not lower than ANSI Class V. When fault isolation is activated, the automatic shut-off valve 14 closes the inlet and outlet pipes of the fault chamber to prevent the electrolyte from continuing to flow in and to prevent the continued generation of gas in the fault chamber.

[0039] Safety control unit 30 The safety control unit 30 is the decision-making layer of the system, and it is connected to the indicator prediction module 29, the fault isolation system 6 and the main power supply of the electrolytic cell, respectively. The core configuration logic of the safety control unit 30 is as follows: when the indicator prediction module 29 determines that the voltage of any single cell of electrolysis chamber 2 is ≥2.5V, the safety control unit 30 immediately controls the main power supply of the electrolysis cell to stop and starts the fault isolation system 6 to cut off the electrical circuit 7 and fluid circuit 8 of the electrolysis chamber 2 with the voltage exceeding the limit, thereby achieving fault isolation.

[0040] The specific execution sequence is as follows: T00ms: Received a Level 3 action signal and issued a main power supply shutdown command; T0+0.5s: The main circuit current drops to 0A; T0+1.0s: Drive electrical isolation unit 9 and automatically connect bypass wire 10; T0+2.0s: Drive fluid isolation unit 11 to close the inlet and outlet valves of the fault chamber; T0+3.0s: Confirm isolation complete (bypass on-resistance ≤0.001Ω, valve feedback signal in place); T0+4.0s: Issue a command to restore main power supply (if the system allows automatic restoration); The entire automatic isolation process takes about 4 seconds and has almost no impact on the total output of the electrolyzer.

[0041] The safety control unit 30 is equipped with a manual safety control mode and an automatic safety control mode. When switched to manual safety control mode, a voltage ≥2.5V will only trigger a shutdown and alarm, and will not automatically perform fault isolation. The operator must confirm and then manually initiate the isolation.

[0042] In addition, the system also includes an HMI human-machine interface 35, which is connected to the safety control unit 30 to display the individual voltage, electrolyte temperature, tank pressure data and fault isolation status of each electrolysis chamber 2 in real time, and supports historical data query and parameter setting.

[0043] Example 2: Automatic shutdown and dual isolation of alkaline water electrolyzer when voltage exceeds limit With a certain 200Nm 3 Taking the / h alkaline water electrolysis hydrogen production system as an example, the main body of the electrolyzer 1 consists of 100 electrolysis chambers 2 connected in series. Each chamber has a rated voltage of 2.0V and a normal operating voltage range of 1.9V~2.1V. The electrolyte circulation system supplies 30% KOH solution at a flow rate of 12L / min per chamber, and the temperature is controlled at 80±2℃.

[0044] Data acquisition module 28 scans the voltage of all chambers at a frequency of 20Hz. One day, due to partial blockage of the inlet filter in chamber number 67, the liquid supply gradually decreased, and the voltage began to rise from 2.05V. 0 seconds, voltage 2.05V, normal; 30 seconds, voltage 2.28V, below threshold; 55 seconds, voltage 2.31V, triggering a level 1 warning, the HMI human-machine interface displays "Attention: Voltage No. 67 is too high"; 70 seconds, voltage 2.41V, triggering a level 2 warning, the audible and visual alarm "Voltage No. 67 alarm, check recommended"; 80 seconds, voltage 2.51V, triggering a level 3 action.

[0045] After receiving the Level 3 action signal, the safety control unit 30 executes the following timing control program: T0+0ms: A main power supply shutdown command is issued, and the main contactor disconnects; T0+0ms: A command to prohibit high-flow-rate liquid supply is issued, and the circulation pump speed is reduced to 10%; T0+0.4s: The current drops from 3000A to 0A, confirming that the shutdown is complete; T0+1.0s: A start command is sent to the fault isolation system 6. The automatic quick-connect connectors on the positive terminal 3 of compartment 67 and the negative terminal 4 of compartment 68 are activated, and the bypass lead 10 completes the connection within 0.3 seconds. The measured bypass resistance is 0.0007Ω. T0+1.5s: Fault isolation system 6 performs fluid isolation, actuating the automatic shut-off valve 14 on the inlet pipe 12 and outlet pipe 13 of chamber 67. The valve closes within 0.6 seconds. T0+2.5s: The system confirms that isolation is complete and issues a power restoration command; T0+4.0s: Electrolytic cell body 1 resumes operation at the rated current of 3000A.

[0046] The entire process took 4 seconds. The voltage of cells 68 to 100 returned to the normal range (1.95V~2.08V), and the voltage of cell 67 dropped to 0V (no current flow), stopping the electrolyte flow into that cell. The surface temperature of bypass lead 10 was 36℃ (ambient temperature 30℃), indicating safety and controllability. The HMI (Human-Machine Interface) 35 displayed: "Fault No.: F-2025-001; Fault Cell: 67; Trigger Voltage: 2.51V; Time: 2025-XX-XX 10:32:80.000; Status: Isolated, awaiting manual reset."

[0047] Example 3: Status Locking and Manual Reset After Fault Isolation Following Example 2, maintenance personnel inspected compartment 67 on the scheduled maintenance day. It was confirmed that the fault was caused by a clogged inlet filter leading to insufficient liquid supply. After replacing the filter, the compartment returned to normal.

[0048] Maintenance personnel perform a reset operation through the HMI (Human-Machine Interface) 35: enter the reset password → select fault number F-2025-001 → confirm reset. The system unlocks the compartment, the electrical isolation unit 9 disconnects the bypass wire 10, and the fluid isolation unit 11 reopens the inlet and outlet valves. The compartment resumes normal operation.

[0049] The system recorded the following in the reset log: "Fault number F-2025-001 was manually reset by operator XXX at 14:30:00 on 2025-XX-XX".

[0050] Example 4: Voltage Change Rate Judgment Function Predicts Early Faults During operation of a PEM electrolyzer (50 chambers, rated voltage 1.8V), early signs of membrane dryness appeared in chamber number 12. Data acquisition module 28 detected that the voltage rose from 1.75V to 2.28V within 1 second, at a rate of 0.53V / s.

[0051] Although the voltage of 2.28V has not yet reached the first-level warning threshold (2.3V), the voltage change rate monitoring unit 34 (threshold 0.5V / s) triggered a rapid warning. The HMI human-machine interface 35 displays: "Warning: The voltage of cell 12 is rising rapidly (0.53V / s), which may be due to membrane dryness or a partial short circuit. Please check."

[0052] After receiving the warning, the maintenance personnel promptly adjusted the liquid inlet flow rate of the chamber, and the voltage returned to the normal range, preventing the fault from escalating to 2.5V and triggering a shutdown. This example demonstrates the value of the voltage change rate monitoring unit 34 in early fault prediction.

[0053] Example 5: Voltage Change Rate Auxiliary Criterion to Prevent Missed Detections During the operation of a PEM electrolyzer (70 chambers, rated voltage 1.8V), the diaphragm 22 of chamber 22 suddenly broke down, and the voltage jumped from 1.75V to 2.55V in 0.3 seconds, and then dropped back to 1.2V due to an internal short circuit.

[0054] If relying solely on the criterion of "voltage ≥ 2.5V and sustained," the fault duration is only 0.3 seconds, which might not trigger the system. However, the voltage change rate monitoring unit 34 of the indicator prediction module 29 detects that the rise rate = (2.55 - 1.75) / 0.3 ≈ 2.67V / s > 0.5V / s, and the peak value 2.55V ≥ 2.5V, triggering a level three action. The safety control unit 30 successfully executes shutdown and isolation, preventing the fault from escalating.

[0055] Example 6: Handling sequential faults in multiple small compartments After 18 months of operation, the main body of the electrolytic cell 1 experienced three faulty compartments: compartment 7 (voltage 2.53V), compartment 34 (voltage 2.61V), and compartment 89 (triggered by voltage change rate). The safety control unit 30 incorporates fault queue management. 1. Handling Case 7: Shutdown → Isolation → Recovery (4 seconds); 2. If case number 34 is still detected as abnormal, the isolation process will be triggered again; 3. Handle No. 89.

[0056] The total time for the three isolations was approximately 12 seconds. During this period, the main body of the electrolytic cell 1 only experienced three brief shutdowns, resulting in minimal loss of total output.

[0057] Example 7: Manual Safety Control Mode Operation At manned stations, maintenance personnel switch the safety control unit 30 to "manual safety control mode." When the voltage in compartment 23 rises to 2.52V, the system automatically shuts down and issues an audible and visual alarm. The HMI (Human-Machine Interface) 35 displays "Voltage in compartment 23 exceeds limit, shutdown has occurred, please confirm isolation." After inspecting the site and confirming the fault, the operator presses the "Confirm Bypass" button. The system automatically completes the connection of the bypass wire 10 and closes the valve. Then, pressing "Restore Power" resumes operation. If the fault is determined to be a sensor false alarm, pressing "Reset" and then reclosing the circuit breaker will restore power.

[0058] Example 8: The safety significance of prohibiting high-flow-rate infusion During a certain fault, the voltage of chamber 34 reached 2.52V, triggering a shutdown. The safety control unit 30 cut off the main rectifier power supply and reduced the speed of the circulation pump from the rated 2800rpm to 200rpm (minimum maintenance flow rate). It also sent most of the electrolyte directly back to the circulation tank through the bypass valve, maintaining only a very small flow rate to prevent the circulation pump from running dry.

[0059] The significance of this design is that if the membrane in the fault chamber is perforated, continuing to supply liquid at a high flow rate will cause a large amount of hydrogen and oxygen to mix in the liquid circuit, forming an explosive gas. After stopping the high flow rate liquid supply, the amount of gas generated in the fault chamber drops sharply (because the electrolysis reaction stops), and the residual gas can be safely discharged through the exhaust pipe, significantly reducing the safety risk.

[0060] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electrolytic cell system with fault prediction and automatic isolation function, characterized in that, include: The main body of the electrolytic cell includes multiple electrolytic cells connected in series. Each electrolytic cell has a positive terminal and a negative terminal, and adjacent electrolytic cells are connected in series through an internal conductor. The data acquisition module is used to collect the individual voltage, electrolyte temperature, electrolytic cell operating current, and cell pressure of each electrolysis cell in real time. The fault isolation system, configured in the electrical and fluid circuits of each electrolysis cell, is used to perform independent fault isolation for individual abnormal electrolysis cells; The safety control unit is connected to the data acquisition module, the fault isolation system, and the main power supply of the electrolytic cell, respectively. The safety control unit is configured to: immediately shut down the main power supply of the electrolytic cell when the voltage of any individual cell in the electrolysis chamber is greater than or equal to the safe threshold voltage of the individual cell, and start the fault isolation system to cut off the electrical circuit and fluid circuit of the electrolysis chamber with the voltage exceeding the limit, thereby achieving fault isolation.

2. The electrolytic cell system with fault prediction and automatic isolation function according to claim 1, characterized in that, The safe threshold for the individual cell voltage is 2.5V, the sampling frequency of the data acquisition module is ≥10Hz, and the individual cell voltage measurement accuracy is ≤±0.5%, the electrolyte temperature measurement accuracy is ≤±0.5℃, and the tank pressure measurement accuracy is ≤±1% FS.

3. The electrolytic cell system with fault prediction and automatic isolation function according to claim 1, characterized in that, It also includes an indicator prediction module connected to the data acquisition module, used to predict, provide graded early warnings, and identify anomalies in the electrolysis chamber based on the acquired parameters, and includes: The reference threshold unit has a preset individual cell voltage safety threshold of 2.5V; The trend prediction unit is used to predict the aging, short circuit, membrane fouling or electrolyte abnormality trends of the electrolysis chamber based on the rate of voltage change. The graded early warning unit has built-in multi-level early warning thresholds: Level 1 warning: Individual cell voltage ≥ 2.3V or tank voltage fluctuation ≥ ±10%; Level 2 warning: Individual cell voltage ≥ 2.4V or electrolyte temperature ≥ 85℃ or tank pressure ≥ 1.2 times the normal value; Level 3 action: Individual cell voltage ≥ 2.5V.

4. The electrolytic cell system with fault prediction and automatic isolation function according to claim 3, characterized in that, The indicator prediction module is also equipped with a voltage change rate monitoring unit. When the voltage of any single cell in the electrolysis chamber rises at a rate ≥0.5V / s within 1 second, a rapid early warning is triggered and the safety control unit is notified to strengthen monitoring.

5. The electrolytic cell system with fault prediction and automatic isolation function according to claim 1, characterized in that, The fault isolation system includes: Electrical isolation unit: a spare terminal block configured at the positive and negative terminals of each electrolysis cell, which is fixed in parallel with the positive and negative terminals respectively; and one or more low-resistance bypass wires that can be automatically connected to the spare terminal block, for cutting off the power supply to the abnormal electrolysis cell by bypassing and short-circuiting the abnormal electrolysis cell, so as to remove it from the series working queue. Fluid isolation unit: Automatic shut-off valves configured on the inlet and outlet pipes of each electrolysis chamber are used to close the electrolyte inlet and outlet channels of the chamber, thereby achieving fluid isolation.

6. The electrolytic cell system with fault prediction and automatic isolation function according to claim 1, characterized in that, The safety control unit is equipped with a manual safety control mode and an automatic safety control mode. When switched to manual safety control mode, if the unit voltage is ≥2.5V, only shutdown and alarm will be triggered, and fault isolation will not be automatically performed.

7. The electrolytic cell system with fault prediction and automatic isolation function according to claim 1, characterized in that, After performing shutdown and fault isolation actions, the safety control unit synchronously generates a fault record, marking the abnormal electrolysis chamber number, over-limit voltage value, occurrence time, and fault isolation action status.

8. The electrolytic cell system with fault prediction and automatic isolation function according to claim 1, characterized in that, When multiple electrolysis chambers simultaneously experience a voltage ≥2.5V, the safety control unit executes an emergency shutdown of the entire machine and simultaneously initiates fault isolation for all over-limit electrolysis chambers.

9. The electrolytic cell system with fault prediction and automatic isolation function according to claim 1, characterized in that, It also includes an HMI (Human-Machine Interface) that connects to the safety control unit to display real-time data on the individual cell voltage, electrolyte temperature, tank pressure, and fault isolation status of each electrolysis cell, and supports historical data query and parameter setting.

10. A method for controlling the safety of an electrolytic cell based on the electrolytic cell system with fault prediction and automatic isolation function according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Real-time acquisition of individual cell voltages in each electrolysis chamber; S2, the indicator prediction module performs real-time analysis and trend prediction of individual unit voltage data; S3. Determine if there is a single cell voltage ≥2.5V in the electrolytic cell; S4. If the conditions are met, the safety control unit immediately shuts down the electrolytic cell and activates the fault isolation system to electrically and fluidly isolate the electrolytic cell with the voltage exceeding the limit. S5. After isolation is completed, maintain a safe state and wait for manual reset or automatic system re-inspection.

11. The safety control method of the electrolytic tank of the electrolytic tank system with the fault prediction and automatic isolation function according to claim 10, characterized in that, In step S2, the indicator prediction module issues an early warning based on the rise slope of the individual unit voltage to avoid protection delay caused by sudden voltage jumps.

12. The electrolyzer safety control method of claim 10, wherein, Once the fault is isolated, the system must not be put back into the electrolysis chamber until the fault is eliminated and manually confirmed to be reset.

13. The electrolytic cell safety control method for an electrolytic cell system with fault prediction and automatic isolation functions according to claim 10, characterized in that, When the cell voltage of an electrolytic cell is ≥2.5V, triggering a shutdown, the timing control process is as follows: T0+0ms: Disconnect the main power supply to the electrolytic cell; T0+0ms: The speed of the electrolyte circulation pump is reduced by slowing down, and the electrolyte circulation bypass valve is opened to simultaneously prohibit the large flow of electrolyte supply. T0+0.4s: Current returns to zero; T0+1.0s: The fault electrolysis chamber is electrically bypassed via a bypass wire; T0+1.5s: The fault isolation system performs fluid isolation, activates the automatic switching valve of the fault electrolysis chamber, and closes the valve within 0.6 seconds; T0+2.5s: The system confirms that the fault isolation is complete and issues a power restoration command; T0+4.0s: The main power supply to the electrolytic cell is restored, and the electrolytic cell resumes operation under fault isolation conditions.

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