Two-way parallel control method and system for aluminum oxide concentration of aluminum electrolysis cell

Abstract

The invention discloses a two-way parallel control method for aluminum oxide concentration of an aluminum electrolysis cell, and relates to the technical field of aluminum electrolysis. Comprising the steps that a parallel relay unit is arranged between a cell control machine of the aluminum electrolysis cell and an electrolysis cell executing mechanism, the parallel relay unit receives a first control signal generated by the cell control machine and a second control signal generated by an analysis server at the same time, and the signals are output to the electrolysis cell executing mechanism in parallel; the analysis server collects voltage drop data of a plurality of measurement points on the anode large bus, the column bus and the balance bus, and current of each anode guide rod is obtained through calculation; and the electrolytic cell is divided into a plurality of control areas according to the positions of the blanking points, the concentration of each area is calculated by adopting an area concentration iterative equation, a target area is determined based on concentration distribution, and a second control signal for crust breaking and blanking of the target area is generated. The parallel relay unit is additionally arranged between the cell control machine and the execution mechanism, and the external analysis server is introduced, so that the regionalized aluminum oxide concentration fine control of the traditional aluminum electrolysis cell is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum electrolysis, in particular to a two-path parallel control method and system for alumina concentration of an aluminum electrolysis cell. BACKGROUND

[0002] The aluminum electrolysis cell is the core equipment of the aluminum smelting industry, and its production process usually relies on the real-time collection and analysis of cell voltage and cell current by the cell controller. However, 24 to 56 groups of anodes are often configured in parallel in the electrolytic cell, and the existing black box control architecture based on "dispersed anode - centralized management" can only achieve "one-dimensional" or "point" control, which is difficult to cover complex and dynamic operating conditions.

[0003] Although the signal acquisition and algorithm analysis technology is constantly improving, the field control ecology is still highly heterogeneous: different cell controllers lack unified standards in communication protocols, I / O interfaces, control permissions, emergency stop bypass, minimum action interval, and prohibited time window; different cell types also have significant differences in NB control tempo and actuator process parameters. Under this background, the regional concentration fine control based on anode current and the traditional NB (downloading cycle) full-cell control cannot effectively cooperate at the engineering level: first, regional control requires high-frequency, small-dose, and targeted crust breaking / downloading events, while NB baseline emphasizes global steady-state tempo, which may conflict on the time axis; second, simply adding regional "extra downloading" may break the total feeding budget of the cycle, causing fluctuations in the material balance of the full cell; third, the partition model relies on anode current to estimate local consumption, while the downloading cycle control determines the full-cell state based on equivalent resistance slope / cumulative slope, and the inconsistency of these characteristic quantities leads to mutual interference of strategies. In addition, the safety and reliability of external commands in the field (such as emergency stop priority, communication timeout switching, self-recovery, etc.) are considered, and rigid requirements make it difficult for automatic decision-making to be reliably implemented to the execution level through existing cell control systems, which has become a key bottleneck in further improving control performance, especially in the promotion and application of large cell types.

[0004] In summary, the current system ecology is diversified and the standards are not unified, resulting in a lack of effective coordination between fine regional control driven by anode current and traditional cell control system, and automatic decision-making instructions are difficult to safely and stably transmit to the execution level; there is an urgent need for a technical solution to address the above needs. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a two-path parallel control method and system for alumina concentration of an aluminum electrolysis cell, which realizes the safe coordination of regional alumina concentration fine control and full-cell NB baseline tempo of a traditional aluminum electrolysis cell without changing the control logic of the existing cell controller and the main link of the actuator.

[0006] The specific technical solution is as follows:

[0007] In a first aspect, a method for parallel control of alumina concentration in an aluminum reduction cell includes:

[0008] A parallel relay unit is arranged between a cell controller and an electrolytic cell actuator of the aluminum reduction cell, the parallel relay unit simultaneously receives a first control signal generated by the cell controller and a second control signal generated by an analysis server, and outputs a parallel signal to the electrolytic cell actuator;

[0009] The cell controller collects cell voltage and cell current signals, calculates the total cell alumina concentration and adjusts the discharge interval, and updates the first control signal for crust breaking and discharging based on the discharge interval;

[0010] The analysis server collects voltage drop data of multiple measurement points on the anode busbar, the column busbar and the balance busbar, calculates the current of each anode rod, divides the electrolytic cell into several control regions according to the discharge point position, calculates the concentration of each region using an iterative update equation of regional alumina concentration, determines a target region based on the concentration distribution, and generates a second control signal for crust breaking and discharging in the target region;

[0011] The electrolytic cell actuator performs crust breaking and discharging operations according to the output signal of the parallel relay unit.

[0012] Preferably, the iterative update equation of regional alumina concentration is:

[0013] Ct = Ct-1 + Cin + Cout + f(It)

[0014] Wherein: Ct is the alumina concentration in the region at the current time; Ct-1 is the alumina concentration in the region at the previous time; Cin is the alumina concentration flowing into the region; Cout is the alumina concentration flowing out of the region; f(It) is the alumina consumption rate related to the anode current.

[0015] Preferably, the analysis server calculates the alumina concentration of each control region in a control period of 8 hours, determines the total amount of alumina to be supplemented and the corresponding number of additional discharges in the period according to the concentration deviation of the target region, and distributes the number of additional discharges in the available time window of the discharge interval at equal intervals.

[0016] Preferably, the electrolytic cell is divided into 6 control regions according to the discharge point position, and each control region corresponds to a discharge point.

[0017] Preferably, the total number of voltage detection points is 70; the voltage detection points are fixed to the surface of the busbar by bolts through T-shaped conductive connectors to realize long-term online measurement.

[0018] Preferably, the parallel relay unit extracts the time stamp of the first control signal to obtain a first draw interval sequence NB1, and extracts the time stamp of the second control signal to obtain a second draw interval sequence NB2;

[0019] The rolling difference ΔNB is calculated as the interval average difference between NB2 and NB1, and when |ΔNB|≤ threshold δNB, the time plan of the second control signal is aligned with reference to NB1; when |ΔNB|> δNB, non-urgent regional draw events are suspended or compressed until |ΔNB| returns to the threshold range, or NB1 is directly used according to a preset priority.

[0020] Preferably, the analysis server receives the cell voltage and cell current signals of the electrolytic cell, and calculates the full-cell alumina concentration and the second draw interval as a cooperative reference for generating the second control signal.

[0021] Preferably, the parallel relay unit determines the reference time axis with the first draw interval sequence NB1, and constructs a set of available time windows between adjacent baseline draws; under the constraints of the minimum operation interval Tmin and the post-operation prohibited time window Tban of the same actuator, only the second control signal is allowed to be inserted within the available time window; when the second control signal conflicts with the first control signal within the same time window, the first control signal is executed preferentially, and the second control signal is postponed to the next available time window; when an emergency stop signal is received or communication with the analysis server is detected to be abnormal, the system automatically switches to a mode of executing only the first control signal.

[0022] Preferably, when a hardware emergency stop signal is received, the parallel relay unit unconditionally switches all output control rights to the cell controller; when communication with the analysis server times out, the system automatically switches to the cell controller and can trigger a self-restart attempt to the analysis server, and after communication is restored, the system restores the dual-path parallel working mode.

[0023] In a second aspect, the application discloses an aluminum electrolytic cell alumina concentration dual-path parallel control system, comprising:

[0024] a cell controller for calculating the full-cell alumina concentration based on the cell voltage and cell current signals and adjusting the draw interval, and rolling updating the first control signal of the full-cell crust breaking and draw operation;

[0025] an analysis server for collecting multi-point voltage drops and calculating anode rod currents, dividing multiple control regions, calculating regional concentrations using regional concentration iterative equations, and generating the second control signal;

[0026] an anode current acquisition module installed on the anode busbar, the column busbar and the balance busbar for collecting voltage drop data;

[0027] Parallel relay unit, connecting the tank control machine, analysis server and electrolytic tank execution mechanism, and outputting signals to the electrolytic tank execution mechanism in parallel;

[0028] Execution mechanism, comprising a crust breaking device and a discharging device, for executing the signals output by the parallel relay unit.

[0029] Compared with the prior art, the present application has the following advantages:

[0030] The present application realizes lossless integration and safety enhancement of the existing tank control system. Through the external parallel relay unit, the regional fine control function based on anode current is bypassed as an "additional item" without changing the original tank control machine hardware, control logic and main execution link. This design ensures the absolute priority and continuity of traditional full-tank concentration control (NB beat), and through safety mechanisms such as emergency stop signal priority and communication timeout self-recovery, the system does not reduce the original safety and reliability when introducing new technology, showing strong adaptability to diverse tank control ecologies at home and abroad.

[0031] The present application realizes the leap of alumina concentration distribution in the tank from "point" control to "surface" control, significantly improving uniformity. Through deep analysis of anode current signals and iterative calculation of regional concentration by the analysis server, the present application can sense and actively intervene in the concentration differences in different regions of the tank in real time. Practical application shows that this method can reduce the alumina concentration gradient between half tanks by about 80% (for example, from 0.1% to 0.02%), effectively eliminating problems such as local overheating and anode effect caused by uneven concentration distribution, laying a solid foundation for stable and efficient operation of the electrolytic tank.

[0032] The present application brings direct economic benefits and production index optimization. The uniformity and stability of concentration distribution directly translates into an increase of 0.5% to 1.0% in current efficiency, equivalent to a significant increase in aluminum production under the same power consumption. At the same time, the reduction of anode effect coefficient also reduces greenhouse gas emissions and improves the environmental friendliness of production. With minimal modification cost, the present application realizes the synergistic growth of production efficiency, economic benefit and environmental benefit. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a traditional alumina concentration control logic diagram;

[0034] Figure 2 is a parallel control logic system architecture diagram;

[0035] Figure 3 is a schematic diagram of the terminal position of the anode current online monitoring module;

[0036] Figure 4 is a regional concentration control electrolytic tank partition;

[0037] Figure 5 is a parallel relay unit control logic. DETAILED DESCRIPTION

[0038] The invention is further described in detail by the following embodiments in combination with the accompanying drawings, so that the purposes, technical solutions and technical effects of the invention are more clearly presented.

[0039] As Figure 1 shown, it is a traditional alumina concentration control logic diagram; the traditional alumina concentration is controlled by the pot controller. The pot controller collects the cell voltage and cell current data of the electrolytic cell, and obtains the slope and cumulative slope of the electrolytic cell resistance change, high frequency noise and low frequency noise by conversion into equivalent resistance, filtering and analysis. When the slope and cumulative slope reach the upper limit and lower limit of the alumina concentration, an instruction is issued to adjust the alumina discharge interval (NB - the time interval between two alumina discharges). The instructions for crust breaking and discharging of the electrolytic cell are updated in real time with the adjustment of NB. The traditional alumina control method is point control, which takes the average concentration of the alumina in the whole cell as the monitoring object.

[0040] As Figure 2 shown, the application discloses a kind of double-path parallel control method for alumina concentration of aluminum electrolytic cell, comprising:

[0041] A parallel relay unit is arranged between the pot controller of the aluminum electrolytic cell and the electrolytic cell actuator, and the parallel relay unit simultaneously receives the first control signal generated by the pot controller and the second control signal generated by the analysis server, and outputs the signal to the electrolytic cell actuator. The pot controller collects the cell voltage and cell current signals, calculates the alumina concentration in the whole cell and adjusts the discharge interval, and updates the first control signal for the whole cell crust breaking and discharging based on the discharge interval. The analysis server collects the voltage drop data of multiple measurement points on the anode busbar, column busbar and balance busbar, and calculates the current of each anode lead; the electrolytic cell is divided into several control regions according to the discharge point position, the regional alumina concentration iterative update equation is used to calculate the concentration of each region, and the target region is determined based on the concentration distribution and the second control signal for the target region is generated. The electrolytic cell actuator executes the crust breaking and discharging operation according to the output signal of the parallel relay unit.

[0042] In one aspect, the tank controller uses the collected tank voltage and tank current signals to calculate the full-tank alumina concentration according to a corresponding relationship model between the full-tank alumina concentration and the tank electrical parameters, and dynamically adjusts the discharging interval, thereby generating a first control signal for full-tank crust breaking and discharging operations, ensuring that the full-tank concentration is maintained within a reasonable range. On the other hand, the analysis server obtains multi-point voltage drop data on the anode busbar, column busbar and balance busbar based on the anode current acquisition module, calculates the current of each anode guide rod according to Ohm's law and busbar structure parameters, divides the electrolytic tank into several control areas in combination with the distribution of discharging points in the electrolytic tank, and calculates the real-time concentration of each control area through the iterative equation of regional alumina concentration, determines the target area to be regulated according to the concentration deviation of each area, and generates a second control signal for the target area. At the same time, the parallel relay unit serves as the core of the coordination and output of the dual-channel control signal, performs time axis alignment, conflict processing and abnormal switching control on the two control signals, and finally outputs the coordinated control signal to the actuator, realizing the orderly progress of dual-channel parallel control.

[0043] The existing regional concentration calculation method ignores the flow of alumina between regions and the consumption difference related to anode current, making it difficult to accurately reflect the dynamic changes of regional concentration. The iterative equation can more accurately reflect the actual change law of alumina in the electrolytic tank by introducing the concentration at the previous time, the inflow and outflow concentration, and the anode current-related consumption rate, and its effect is to dynamically and accurately calculate the current alumina concentration of each control area, providing reliable data support for accurate identification of target areas and accurate generation of second control signals. The iterative update equation of regional alumina concentration is:

[0044] C t =C t−1 +C in +C out +f(I t )

[0045] In the formula: C t is the current concentration of alumina in the region; C t−1 is the alumina concentration in the region at the previous time; C in is the inflow concentration of alumina in the region; C out is the outflow concentration of alumina in the region; f(I t ) is the alumina consumption rate related to anode current.

[0046] Here, the analysis server calculates the alumina concentration of each control area in a control cycle of 8 hours, determines the total amount of alumina to be supplemented and the corresponding additional number of discharges in the control cycle according to the concentration deviation of the target area, and distributes the additional number of discharges in the available time window of the discharge interval at equal intervals. An 8-hour cycle can balance the accumulation of area concentration deviation and adjustment lag caused by a long control cycle, and increase the calculation load and easily cause control fluctuations caused by a short control cycle. Equal interval distribution of the additional number of discharges can avoid the sudden rise and fall of the alumina concentration in the local area caused by concentrated discharging, and the effect is to achieve the uniformity of alumina supplement, effectively suppress the local concentration fluctuation, and ensure the stable progress of the electrolysis process in each area of the electrolytic cell.

[0047] In an embodiment, the electrolytic cell is divided into 6 control areas according to the position of the discharge point, and each control area corresponds to a discharge point. The division of the 6 control areas can avoid the lack of control precision caused by too few areas, and can avoid the increase of calculation complexity and control response delay caused by too many areas. The independent discharge point corresponding to each area can realize accurate matching of the control action and the area.

[0048] In an embodiment, the total number of voltage detection points is 70; the voltage detection points are fixed on the surface of the busbar by bolts through T-shaped conductive connectors to realize long-term online measurement. The 70 detection points can realize comprehensive coverage of the bus voltage drop, avoid sampling errors caused by single-point or a small number of detection points, and the bolt fixing mode of the T-shaped conductive connector can solve the problem of unstable or failed detection signals caused by poor contact in long-term online measurement.

[0049] The parallel relay unit is the key of the present application, wherein the parallel relay unit extracts the time stamp of the first control signal to obtain the first discharge interval sequence NB1, and extracts the time stamp of the second control signal to obtain the second discharge interval sequence NB2. The rolling difference ΔNB is calculated as the interval average difference of NB2 and NB1. When |ΔNB|≤threshold value δNB, align the time plan of the second control signal based on NB1; when |ΔNB|>δNB, suspend or compress non-urgent area discharge events until |ΔNB| returns to the threshold range, or directly use NB1 according to the preset priority. The discharge intervals of the two control signals may be deviated due to differences in control logic or parameters, and direct execution may cause control conflicts or execution mechanism action disorder. Through threshold value judgment and corresponding strategy, the two intervals can be cooperatively adapted.

[0050] Among them, the analysis server receives the cell voltage and cell current signals of the electrolytic cell, and calculates the total alumina concentration and the second discharge interval, which are used as the cooperative reference for generating the second control signal.

[0051] To ensure the safe and orderly operation of the actuators and the continuity of control during abnormal situations, the parallel relay unit determines the reference time axis using the first feeding interval sequence NB1 and constructs a set of available time windows between two adjacent baseline feeding operations. Under the constraints of the minimum operation interval Tmin and the post-operation prohibition time window Tban for the same actuator, only the second control signal is allowed to be inserted within the available time window. When the second control signal conflicts with the first control signal within the same time window, the first control signal is executed first, and the second control signal is postponed to the next available time window. When an emergency stop signal is received or an abnormality in communication with the parsing server is detected, the system automatically switches to the mode of executing only the first control signal. The actuators have physical operation constraints (such as Tmin and Tban). Directly inserting signals without considering these constraints can easily lead to actuator malfunctions, while signal conflicts can cause operational chaos. In abnormal situations (emergency stop, communication abnormality), it is necessary to ensure uninterrupted control.

[0052] For scenarios involving hardware emergency stops and communication timeouts, more refined switching and recovery strategies are implemented. Upon receiving a hardware emergency stop signal, the parallel relay unit unconditionally switches all output control to the slot controller. When communication with the parsing server times out, it automatically switches to the slot controller and can trigger a self-restart attempt on the parsing server. After communication is restored, the dual-path parallel operating mode is resumed. Hardware emergency stops involve equipment and personnel safety and must be prioritized unconditionally. Communication timeouts mean the second control signal is unreliable, requiring a switch to the reliable first control signal and an attempt to restore communication. The effect is to maximize safety in emergency situations.

[0053] In another embodiment, the present invention discloses a dual-path parallel control system for alumina concentration in an aluminum electrolysis cell, comprising:

[0054] The cell control machine is used to calculate the alumina concentration of the entire cell based on the cell voltage and cell current signals and adjust the feeding interval, and to continuously update the first control signal for the entire cell shelling and feeding operations.

[0055] The analysis server is used to collect voltage drops at multiple points and calculate the anode conductor current, divide the region into multiple control regions, calculate the concentration of each region using the region concentration iteration equation, and generate a second control signal.

[0056] The anode current acquisition module is installed on the anode main bus, column bus, and balance bus to collect voltage drop data.

[0057] The parallel relay unit connects the cell controller, the analysis server, and the electrolytic cell actuator, and outputs signals to the electrolytic cell actuator in parallel.

[0058] The actuator, including a shell-breaking device and a feeding device, is used to execute the signals output by the parallel relay unit.

[0059] This invention achieves precise regional control based on anode current by intelligently inserting a parallel relay unit into the existing control link, without interfering with the original overall control logic of the cell controller. The cell controller continues its traditional operating mode, analyzing the equivalent resistance curve (slope / cumulative slope) of the cell voltage and current to determine the average level of alumina concentration across the entire cell, and adjusts the feeding interval (NB) accordingly, generating shell-breaking and feeding commands covering the entire electrolytic cell: the first control signal. This ensures overall production stability and basic material balance. An external analysis server operates independently, reconstructing the current distribution of each anode by collecting voltage drops at multiple points on the anode busbar, column busbar, and balance busbar. Based on this, the electrolytic cell is divided into several control areas according to physical feeding points, and the alumina concentration of each area is calculated in real time using a regional concentration iteration equation. When a low concentration is detected in a specific area, an additional shell-breaking and feeding command is generated for that area: the second control signal, to achieve "targeted" feeding. The parallel relay unit simultaneously receives both control signals. Its internal logic uses the first control signal of the slot controller as an unshakeable "reference time axis." It only allows the insertion of the parsing server's regional optimization instructions within a "safe time window" between two adjacent full-slot unloading actions, strictly adhering to physical constraints such as the minimum operating interval of the actuator. When two instructions conflict in time, the full-slot instruction from the slot controller is executed without exception, while the regional instruction is postponed, thus ensuring that the full-slot control cycle is unaffected. This embodies the fundamental principle of "without modification."

[0060] This section further explains the online acquisition of anode current distribution; voltage drops are collected at intervals along the anode busbar, column busbar, and balance busbar between every two anode conductors. The anode current acquisition terminals are T-shaped plates, bolted to the busbars. A 500kA electrolytic cell requires 70 voltage drop acquisition points along the anode busbar, column busbar, and balance busbar. Figure 3 As shown, the current here can be calculated using Ohm's law, and then the current in the anode conductor can be calculated using Kirchhoff's law. Figure 5 The real-time display of the calculated anode current is provided. The accuracy of automatic on-site measurement compared to manual measurement is <5%.

[0061] Regional alumina control logic: Currently, there are 6 points in the electrolytic cell with uniform feeding. Regional concentration control of the electrolytic cell involves active intervention in the concentration distribution, controlling the overall concentration distribution by adjusting the feeding rate at these six points. The aluminum electrolytic cell is divided into 6 zones according to the feeding location, such as... Figure 4 As shown, the alumina concentration for each region is calculated as follows:

[0062] C t =C t−1 +C in +C out +f(It )

[0063] In the formula: C t C represents the alumina concentration in the region at the current moment. t−1 C represents the alumina concentration in the region at the previous time step. in The concentration of alumina in the inflow area; C out f(I) represents the alumina concentration in the outflow region. t The alumina consumption rate is related to the anolyte current. This technology can display the alumina concentration in each region in real time.

[0064] like Figure 5 The diagram shown is the control logic diagram of a parallel relay unit. The main functions of the parallel relay unit include:

[0065] (1) Remote server control: Receive and parse server instructions (second control instructions) to realize remote control of the solenoid valve.

[0066] (2) Seamless control switching: Seamless switching is achieved between server control (second control command) and Lideer control (first control command) to ensure the continuity of the production process.

[0067] (3) Emergency stop safety function: When a hardware emergency stop signal is received, all output control rights are unconditionally switched to the tank control system to ensure equipment safety.

[0068] (4) Communication timeout self-recovery: When communication with the parsing server times out, it automatically switches to the slot control system and can trigger the device to restart and attempt to recover the system.

[0069] After adopting the above embodiments, the half-cell concentrations in the electrolytic cell were measured to be 1.82% and 1.80%, respectively, and the alumina concentration gradient was reduced by 80% compared to before the technology was adopted. The current efficiency of the electrolytic cell increased by 0.5%-1.0%, which shows that the current efficiency of the electrolytic cell of the present invention is improved compared to the prior art. Moreover, this can be optimized for existing electrolytic cells without modifying the existing structure, which greatly enhances adaptability and ensures the smooth and safe operation of production.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the patent application of the present invention. All equivalent changes, substitutions or modifications made within the technical spirit and principles indicated by the present invention should be included within the scope of patent protection covered by the present invention.

Claims

1. A dual-path parallel control method for alumina concentration in an aluminum electrolytic cell, characterized in that, include: A parallel relay unit is set between the cell control machine and the cell actuator of the aluminum electrolysis cell. The parallel relay unit simultaneously receives the first control signal generated by the cell control machine and the second control signal generated by the analysis server, and outputs the signals to the cell actuator in parallel. The cell control machine collects cell voltage and cell current signals, calculates the alumina concentration of the entire cell and adjusts the feeding interval, and updates the first control signal for the entire cell shelling and feeding based on the feeding interval; The analysis server collects voltage drop data from multiple measurement points on the anode busbar, column busbar, and balance busbar, and calculates the current of each anode conductor. The electrolytic cell is divided into several control zones according to the location of the feeding point. The concentration of each zone is calculated by using the iterative update equation of the alumina concentration of the zone. The target zone is determined based on the concentration distribution, and a second control signal for shelling and feeding is generated for the target zone. The electrolytic cell actuator performs shelling and unloading operations based on the output signal of the parallel relay unit.

2. The dual-path parallel control method for alumina concentration in an aluminum electrolytic cell according to claim 1, characterized in that: The iterative update equation for the alumina concentration in the region is: C t =C t−1 +C in +C out +f(I t ) In the formula: C t C represents the alumina concentration in the region at the current moment. t−1 C represents the alumina concentration in the region at the previous time step. in The concentration of alumina in the inflow area; C out f(I) represents the alumina concentration in the outflow region. t () represents the alumina consumption rate related to the anodic current.

3. The dual-path parallel control method for alumina concentration in an aluminum electrolytic cell according to claim 1, characterized in that: The analysis server calculates the alumina concentration of each control area in a rolling 8-hour control cycle. Based on the concentration deviation of the target area, it determines the total amount of alumina to be replenished within the cycle and the corresponding number of additional feedings. The additional feedings are then distributed at equal intervals within the available time window of the feeding interval.

4. The dual-path parallel control method for alumina concentration in an aluminum electrolytic cell according to claim 1, characterized in that: The electrolytic cell is divided into 6 control areas according to the feeding point position, and each control area corresponds to a feeding point.

5. The dual-path parallel control method for alumina concentration in an aluminum electrolytic cell according to claim 1, characterized in that: The total number of voltage detection points is 70; the voltage detection points are fixed to the busbar surface by bolts using T-shaped conductive connectors to achieve long-term online measurement.

6. The dual-path parallel control method for alumina concentration in an aluminum electrolytic cell according to claim 1, characterized in that, The parallel relay unit extracts the timestamp of the first control signal to obtain the first feeding interval sequence NB1, and extracts the timestamp of the second control signal to obtain the second feeding interval sequence NB2. The rolling difference ΔNB is calculated as the average difference between NB2 and NB1. When |ΔNB|≤ threshold δNB, the timing of the second control signal is aligned with NB1 as the reference. When |ΔNB|>δNB, non-urgent area material feeding events are paused or compressed until |ΔNB| returns to the threshold range, or NB1 is directly adopted according to the preset priority.

7. The dual-path parallel control method for alumina concentration in an aluminum electrolytic cell according to claim 6, characterized in that: The analysis server receives the cell voltage and cell current signals of the electrolytic cell, and calculates the total alumina concentration and the second feeding interval as a collaborative reference for generating the second control signal.

8. The dual-path parallel control method for alumina concentration in an aluminum electrolytic cell according to claim 7, characterized in that: The parallel relay unit determines the reference time axis using the first feeding interval sequence NB1 and constructs a set of available time windows between two adjacent baseline feedings. Under the constraints of the minimum operation interval Tmin and the post-operation prohibition time window Tban of the same actuator, only the second control signal is allowed to be inserted within the available time window. When the second control signal and the first control signal conflict within the same time window, the first control signal is executed first, and the second control signal is postponed to the next available time window. When an emergency stop signal is received or an abnormality in communication with the parsing server is detected, the system automatically switches to the mode of executing only the first control signal.

9. The dual-path parallel control method for alumina concentration in an aluminum electrolytic cell according to claim 1, characterized in that: When a hardware emergency stop signal is received, the parallel relay unit unconditionally switches all output control to the slot controller; when communication with the parsing server times out, it automatically switches to the slot controller and can trigger a self-restart attempt on the parsing server, and resumes dual-path parallel operation mode after communication is restored.

10. A dual-path parallel control system for alumina concentration in an aluminum electrolytic cell for implementing the method of any one of claims 1 to 9, characterized in that, include: The cell control machine is used to calculate the alumina concentration of the entire cell based on the cell voltage and cell current signals and adjust the feeding interval, and to continuously update the first control signal for the entire cell shelling and feeding operations; The analysis server is used to collect voltage drops at multiple points and calculate the anode rod current, divide multiple control regions, calculate the concentration of each region using the region concentration iteration equation, and generate a second control signal. The anode current acquisition module is installed on the anode main bus, column bus, and balance bus to collect voltage drop data. A parallel relay unit connects the cell controller, the analysis server, and the electrolytic cell actuator, and outputs signals to the electrolytic cell actuator in parallel. The actuator, including a shell-breaking device and a feeding device, is used to execute the signals output by the parallel relay unit.

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